I have the 640XL to play with now (just a sample for testing networking things).
I think it's quite a decent phone for people that don't care about smartphones, like older people or people that can't read the tiny screens of dumb phones and feature phones any more.
But to be honest, there is no comparison between any of the Microsoft phones and Android phones... there just isn't lolz... Android now has a better app ecosystem than Windows desktop, and Microsoft mobile is lightyears behind on what's available for Windows Desktop. Even the Microsoft developed apps totally suck in comparison to modern Android offerings.
An example of the huge difference in software evolution: on Android, Google offers the new Snapseed 2.0 for free, and it's really powerful, it's basically the same as Color FX Pro, a paid extension/plug-in for Adobe Lightroom and Corel PhotoPaint. Snapseed 2.0 was developed by Nik Software in Lübeck in Germany, with a focus on maximizing performance and new features, whilst offering the image processing quality of Nik professional products. About a month after the release of Snapseed 2.0, Adobe brought out Lightroom 6 for Windows Desktop. It is a complete joke, even less performance than before, and even the (one guy) developer that was hired to make lightroom faster, came forward to say that on most systems and in most applications, it's better to turn the "acceleration technology" off to prevent Lightroom 6 from even being slower than Lightroom 5. That's expensive Windows desktop software with years of experience, coming out after new free Android software that is superfast on ARM processors and gives much better results in an era where even RAW processing, (one of the weakest points of Adobe, in that in-camera RAW processing gives much better results on every single camera system that came out in the last 4 years or so than Adobe Camera Raw), is a thing of the past for people that are using modern camera systems. Dynamic masking etc, things that are in Snapseed 2.0, aren't even in Adobe Photoshop CC, let alone in Lightroom, where the cloning tool hasn't evolved since 2010 or so.
That ever widening gap between the features, performance, user friendliness, accessibility and economy of the much more evolved apps for linux (incl. CrOS), android and iOS on the one hand, and Windows Desktop and Mobile on the other hand, is just something that will never be closed again, ever. That should be more than clear by now. Microsoft is now going to buy Blackberry, about 6 years too late. They are desperate for market share, on ALL post-PC platforms. The lack of market share and the complete lack of credibility in the modern application software landscape, leads to ever less evolution in the software and as a platform, so even the new software products that are released in the entire Microsoft ecosystem, are perceived as useless and old right at the time of release. There is absolutely no difference there between the desktop and mobile windows ecosystems.
That being said, some user groups just don't need more than an oldfashioned, unflexible and very feature- and performance- limited solution. IF Microsoft would be able to respect privacy and consumer protection legislation, and completely derogate and deny the Patriot Act and its human rights violating consequences outside of the US, in other words, if Microsoft would move its headquarters and legal forum outside of the US and other Gitmo countries, Microsoft could profit from one thing that Google is doing completely wrong for the moment, just like Amazon, Facebook, and the rest of those... respect for privacy and human rights.
If Microsoft would completely change course in that aspect, and start to respect its customers by preserving their rights, Microsoft would instantly gain a lot of customer base from Google and Amazon, and Microsoft would be a competitive player again. But Microsoft has been the worst offender in that department since the 80's, building NSA spyware right into its software and even hardware products, and even recently Satya Nadella stated that women shouldn't ever ask for a raise at Microsoft... so that's the mindset Microsoft is trapped in, and sadly enough, they have pretty much missed all opportunity to snap out of it, and I think they will never again connect to the present and future computing world.
Of course, the bills for developing network compatibility for Microsoft mobile devices are still being paid for the moment, so the basic functionality is guaranteed on most infrastructures, so there is no real reason to say that these devices do not function... they are dirt cheap, and they provide basic functionality. However... ANY android phone of the same price, but also of a lower or higher price, will offer more functionality, will offer the possibility to upgrade the firmware, to root the device and increase the functionality and security ever further, will offer the possibility to install Android or another linux-based mobile operating system without Google Apps, for even more flexibility and privacy, etc... and those are things that aren't possible with a Windows Phone, because that phone is locked to Windows only, and Microsoft will not update the firmware of that device to a more recent version with more functionality or bug fixes, they just won't, because they've never done that.