THE GOOD The Microsoft Lumia 640 XL LTE has a bright 5.7-inch screen, works on LTE networks, and has an impressive rear camera and long-lasting battery life.

THE BAD The 720p resolution makes for a lower pixel density than you may want. The processor is a little under-specced for power-users, and the plastic casing can't match the premium feel of some phones.

THE BOTTOM LINE It's no flagship, but the Microsoft Lumia 640 XL LTE offers a solid big-screen experience at a budget price point that's hard to beat.

If you're after a budget smartphone, then the biggest compromise you'll probably have to make is on the camera -- it's just not cost-effective to get the required lens in a cheaper phone. Luckily, Microsoft has found a way to put a quality camera in its newest big-screen phone without sticking on a big price mark-up.

Microsoft Devices' Lumia 640 XL LTE is the souped-up version of the company's 5-inch Lumia 640. The XL ups the screen size to 5.7-inches and adds 4G connectivity, while popping a significantly bigger 13-megapixel camera on the rear, a 5-megapixel one on the front and a 3,000mAh battery inside. Even better, it does all this while maintaining a respectably low price: just $240, £219 in the UK and AU$399 in Australia.

My colleague Andrew Hoyle was quite effusive about the smaller Lumia 640, calling it "everything you'd hope for from a budget phone." But, bearing in mind the XL has the exact same processor, storage and RAM as the smaller model, are these additions worth the extra cost?

A quick note: there are a couple of different variants of the Lumia 640 XL available, including a dual-SIM model and one without the LTE offering. The model reviewed here is a version with a single SIM slot and an LTE 4G modem.

View Full Gallery (9 Photos)Nic Healey/CNET

Design

157.9 x 81.5 x 9mm (6.22 x 3.21 x 0.35 inches)

171g (6.3 oz.)

In an ocean of black handsets, the Lumia 640 XL stands out like some sort of exotic fish. Yes, you can still get it in black or white, but the blue -- wait, make that "cyan" -- review unit that I had in the office was actually quite refreshing.

Even better, the casing on the 640 XL is a matte finish, unlike the gloss on its smaller sibling. I've never been a fan of a piano-finish as they seem designed purely to collect fingerprints, so the XL gets extra points just for that.

The case, like much of the Lumia range, simply pops off to allow access to the SIM and MicroSD slots, so it can be replaced or even swapped back and forth as your mood takes you.

Compared to all-metal designs like the HTC One M9 or the glass backs of the Xperia Z3 and Galaxy S6, the Lumia does feel a little plastic and toylike, but it's actually a solidly made device. It feels good to use, and the matte casing adds a small amount of texture for less chance of slippage.

View Full Gallery (9 Photos)Dave Cheng/CNET

The 640 XL measures 157.9 x 81.5 x 9mm (6.22 x 3.21 x 0.35 inches) and tips the scales at 171g (6.3 oz.). That makes it about 5g lighter and slightly larger than the Samsung Galaxy Note 4, which has the same screen size.

So while it doesn't match the premium feel of those flagships, it's not really trying to -- and it also isn't matching their premium prices either. For the cost of one 32GB Galaxy S6 Edge, you can get nearly three Lumia 640 XLs.

The XL also features something that some phones are lacking these days: a microSD slot. Like the 5-inch 640, you'll be needing to make use of it. The XL has the same rather basic 8GB of internal storage.

Display

5.7-inch IPS screen

1,280 x 720 pixels

259 pixels per square inch

The 5.7-inch IPS screen on the XL might be bigger than the base 640, but it has the exact same resolution of 1,280x720 pixels. This means the XL actually has a lower pixel density than its smaller cousin -- 259ppi versus 294ppi. (For some more context, the 1,440x2,560-pixel Galaxy S6 has around 577 ppi.)

Depending on how good your eyesight is, this might be a sticking point. As a nearsighted glasses-wearer, I didn't see any problem with the XL. Yes, it's noticeably not as crisp as some of the super-high-res displays out there, but I was very content watching streaming video from the Windows Phone Netflix app and had no issue with Web browsing or viewing photos.

View Full Gallery (9 Photos)The Lumia 640 XL LTE vs. the 5-inch 640.Dave Cheng/CNET

The colours are rich and bright, and the phone has good contrast, which is arguably a little more important in a smartphone display. According to Microsoft, the 640 XL also has "sunlight readability enhancements," and they're certainly working. On a glare-heavy Sydney autumn day, the XL was easy to read while trooping around outdoors.

Software and performance

Windows Phone using the Denim Update

1.2GHz Snapdragon 400 processor

1GB of RAM and 8GB of storage

MicroSD slot supports up to 128GB

The 640 XL is running the same version of Windows Phone 8.1 as the 5-inch 640, with all the same benefits and disadvantages. It's also packing the exact same processor and memory, a 1.2GHz Snapdragon 400 and 1GB of RAM. You can read the performance section of the Lumia 640 review for a full rundown.

Essentially, the XL offers a smooth experience when it comes to basic use and, while that processor isn't going to set any speed records, the only time it's noticeably slow is when the phone is a booting up. It takes around 25 seconds from pressing the power button to when you can start using your Lumia.

As someone who's been reviewing Windows-based phones for a few years now, I will say that the Windows App Store has vastly improved from its days of resembling a Wild West town, with searches for apps either offering tumbleweeds blowing in the wind or an assortment of unsavoury options that didn't quite look right. In fact, as soon as Jawbone gets the app for its Up fitness band over, I could be sold on making a full switch from Android.

View Full Gallery (9 Photos)Diagnostic LTE tests in San Francisco using Speedtest.net.Jessica Dolcourt/CNET

Over on the LTE side of things, the XL definitely delivers. It's a category 4 device -- that's a theoretical top download speed of 150Mbps. You don't get those speeds, of course, but testing around the Sydney central business district and Inner West suburbs, I saw a top speed of 56Mbps down and an average of between 25 and 30Mbps. Upload was, as usual, lower, but averaged out to a respectable 12Mbps. Yes, the Category 6 phones that offer carrier aggregation will leave the XL in the dust, but it's not too long ago that the idea of 4G phone at this price point would have been a pipe dream.

In San Francisco on AT&T's network, download speeds typically ranged from 8Mbps down to 17Mbps down, but spiked at 33Mbps down, as tested on the Speedtest.net diagnostic app. Uplink speeds spanned 4.5 to 10.3 Mbps. These are respectable, but not quite as fast as we've seen on other high-end phones. That said, LTE speeds vary dramatically by time of day and exact location, so your speed situation could be very different depending on where you live.

Camera

13-megapixel rear camera

Zeiss optics

5-megapixel front camera

The XL improves on the 640 in both rear and front cameras. The front jumps from an underwhelming 0.9-megapixel to 5, which is going to keep you happy for both selfies and Skype calls.

But it's the 13-megapixel snapper on the rear -- complete with German-made Zeiss optics -- that's the most marked improvement. That's letting you take 4,128x3,096 resolution photos (far, far better than the screen can display) and 1080p Full-HD video -- also at a higher res than the screen can display.

It's all done with the Lumia Camera software, which has great autofocus features for anyone who just likes to take a happy snap every now and then but also lets you manually adjust ISO, white balance, shutter speed, brightness and focus if you're photographically minded and feel like playing around.