I just scooped a Mi4 LTE from eBay to replace my 1520. It still updating apps currently. Microsoft should create more ROMs, kinda like Cyanogen mod. I bought the Mi4 because when I start pulling my hair out from W10M, I can just reflash it back to Android.
*Update*
I've had the opportunity to use it a full day, and its a very nice phone. I loaded build 10586.36 on it and while it still eats through the battery, it still lasts a full day. I still get random reboots when switching back from kids corner, It gets warm to the touch, and the entire "Extras" option is missing in the settings. Besides the omission of the 'Extras" menu, everything I just mentioned also happens to my 1520. Oddly, W10M displays that the Mi4 has 3.5Gb of RAM instead of the 3GB listed by Android. I paid under $150 US for a used but excellent conditioned model, which has the better specs of any Windows Phone besides the Lumai 950/XL.
*Update 2*
Apps that offer DRM videos like Netflix or Flixster will not allow video to play on my device. I've rebooted the device, uninstalled and reinstalled the apps, and even performed a hard reset. No Netflix and its completely useless in North America.