I have long wanted a secondary phone. I happened to see the MS Lumia 735 at a Verizon store recently and liked what I saw. Granted the screen is much smaller than the iPhone 6 Plus, but that's OK. I didn't need another high-end phone. I have been interested in the Windows Phone OS for some time and when I heard the 735 was on the list to get Windows 10, it made the phone even more attractive. The phone is also VERY budget friendly as far as the retail price goes (compared to the hideously expensive iPhone). Having had the phone for nearly a month, so far, so good. The Windows Phone OS is awesome. I really like the transparent tiles that reveal a background image. The phone is smooth and responsive. It's also a good size. Not a phablet, not a micro-phone. It's slightly smaller than my old Droid DNA. The screen size is 4.7 inches. I found the phone easy to set up and use, right from the get-go. Having a Windows PC helps. Below are the Pros and Cons: Pros: Windows 8.1 Denim UI/Upgrade to Windows 10 when released Live tiles Removable/replaceable battery Memory expansion/SD card capability Qi wireless charging ability PC/Smartphone integration with upcoming Windows 10 Good call quality/sound quality 4.7 inch screen - not too big, not too small Smooth OS operation Good signal quality Ease of settings Lock screen notifications/information Lightweight Incredibly inexpensive ($192 outright/$8 per mo. on payment plan) Call/SMS block feature Light or Dark background field Cortana Downloadable maps for offline use Excellent MS Office integration (of course) Decent customizeability Cons: Poor app selection/Apps on iOS & Android missing for Windows Overall weak app ecosystem Average battery life Power/Awake button too close to volume controls Marginal WiFi reception Poor auto-brightness regulation Less expansive settings options compared to iOS & Android Poor ringtone/notification sound selections Overall, the cons are less of an issue than they might sound. I am comparing this phone to the iPhone 6 Plus and HTC Droid DNA I have. The Lumia 735 holds its own against the both of them, but does not match the iPhone overall. The Lumia works great as a secondary phone. It does everything I need it to and does it well. The Windows Phone OS is fantastic and definitely different from iOS and Android. The largest drawback is the app selection. I could never rely on the Lumia to be my main phone, as it has nowhere near the amount of parallel apps I have on the iPhone. For me, Windows has barely 30% of similar apps I use on the iPhone and Droid DNA. Not a deal-breaker, but a significant disadvantage. Windows really has a great operating system. If they can allow for Android crossover app functionality (which I hear they are aiming for), it could help the OS thrive and survive. They cannot live on the pathetic app selection they currently have. Overall, I'm glad I got the phone.
Facebook's Pages app, the two credit unions I have, Google Wallet, Yahoo Sports, SigAlert, KABC and KNBC local L.A. TV station apps, Citymapper, Co-op ATM locator, Co-op Shared Branch locator, Costco, several local grocery store chain apps, and most importantly - Google Voice. With each of the apps mentioned, both are on iOS and Android. These are apps I use regularly and rely on. Windows app functionality leaves a lot to be desired with some apps, as compared to that app's Android or iOS version. Apps do so much more with the latter two than with Windows. It's not that the Windows version is bad, just weak compared to their cousin versions on the other OS's.
Windows Phones are great budget/second phones. The OS is well made, like BB10, just the lack of apps is what usually stops people from making it their primary phone. And as you say, the price/quality is unbelievably good.
I, too, have a Lumia 735. I got mine when I had to have my Note 4 repaired. Comparing to my Note 4, I wasn't impressed with the signal on mine; it was slightly worse than my Note 4. And I also agree, the lack of apps is really a deal breaker for me because I use and prefer apps on Android. Right now, I plopped my T-Mobile SIM in it just to give the SIM a home.