Advice on choosing hardware after reading ‘Start Here’ post

Hi,

Im pretty new to Kodi, been playing with the PC version for a few weeks.
The other day I installed Kodi 14.2 on my AppleTV2 because ultimately I want to be able to watch it on my big TV (not using computer output to TV). I was pretty disappointed with the results (constant crashing ans jerky picture). Im sure a lot has to to with the outdated version of Kodi and the lack of horsepower of the ATV.

I read the ‘START HERE’ post but still have some questions and need some advice about what hardware I should try.

My need as are pretty basic, my TV (really a large monitor) only is 720p but I need and optical audio out on the Kodi device since the monitor doesn’t have audio. Looking for a more stable device then ATV2 and hope to eventually be able to set it up so it is more appliance like (and wife friendly). Fairly small footprint and low power usage would be nice (ie not computer based).

I was considering one of the FireTV devices. Is the Kodi experience going to be much better than with ATV?
If I do go with a FireTV are the Gen2 significantly better (ie I prefer the built in optical output on G1)?

Thoughts on the FireTV or recommendations meeting my criteria would be appreciated.