I have 2 Ecobee3s that I must say I've been pretty happy with so far. I've only had them for just under 1 year so I can't evaluate their long-term reliability yet, but they were easy to install and configure, and both the Android app and web interface work well.
My daughter has a Nest thermostat that she got for free from her electricity provider about 8 months ago. She's not what you'd call a technology power-user, but she hasn't had any complaints about it yet. What sort of problems do you have with yours?