After the EVO 3D... lets see.
1) Insane ULA agreements. (Not only was android ULAs and the Google driver ULAs invasive, one had to deal with HTC's too.) I almost took the phone back after reading it. You are selling your soul... nothing is free.
2) Lack of Support - literally NONE.
3) Point of contact... none? So one has to go after HTC, Android, the programmers for the Apps that refuse to work or who wrote the drivers? Blue tooth pains too.
4) Hardware, Crashing... Poor battery life. Slow...
5) Firmware updates... They just stopped trying on the EVO 3D and ignored us.
I picked up the flagship model and was stuck with it, had to have it fixed several times... ruined an interview trying to find my resume to send extra copies...
BS BS BS BS.
I may get flamed, but I went to a Lumia 935, which worked 99% of the time. The ULAs are clearly written and across the board. Most importantly: I can update contacts on the phone... and they are updated at outlook.com... no lost contacts or new phone numbers being overwritten. Cortana actually works. One drive, camera roll.. Bluetooth devices work like headsets and heart monitors. Then there is Office lens...- awesome!
Much better service and only two people to go to: Microsoft or ATT.
The Lumias are much more secure! (better than IOS or Android)
Sure... the apps are a little lackluster if you want games, but I don't need games.
Microsoft is not 100% but I trust them more, know I can get help and only really need to go to one place, the service is very good and my information is kept private... and the updates keep coming.
Why would I ever want to wrap another layer of BS and lack of privacy with HTC?
As far as iPhones... They seem to always work. I don't go that way, nor do I care to... but no problems with girlfriend's phone... although it is very under-used.