I have purchased Fire TV both Gen1 and Gen2. There is lot of difference between these 2. Gen1 is awesome, still i am using it. when i use fast.com, i get 40 Mbps speed. and there is no issue with video playing on Prime, Sunnxt, Zee5, Hotstar, youtube.. etc
Gen2, thought of upgrading to Gen2, as of now i have returned 2 sticks and decided not to purchase again, thought problem is with stick, now i realized its manufacturing defect. This one sucks. it doesn't have capacity to utilize your internet speed, validated on Fast.com speed is 300 kbps, device heats up. it have all problems. In 15 mins, video stuck and buffers for at least 30 times.. You will be frustrated while watching anything on this one. The same apps on Gen1 is working with out any issues.
Only good thing in this version is volume controlled remote with power on/off button that control your TV. I missed these features in Gen1. anyway, if its not useful for playing any video, i don't have any use with this one. So back to Gen1 Fire TV.
Seriously, if you have Gen1, better don't upgrade to Gen2 at least till Amazon launches stabilized one.