Sign into an existing account

I would like to know a bit more before I go tinkering with this (I'm not buying it to play steam games, of anything I'll be playing GoG games or flash games on it).

Do the different versions really make a difference? It talks about faster ssds, but they all take a micro SD card, right? So I should be able to get a quality SD card (for cheaper than staam's mark ups for disk space) and run off there, right?

How well does it run windows programs