I used to be affiliated with the company. I got a prototype and promoted the hell out of it on my Youtube channel when the Kickstarter was going on and I also worked the booth at PAX East in 2013. (I'm too new here to post links but just look up "Nick Nillo" and you'll find my old channel)
The emulators that are currently running on it work great. But.... if you're buying it in the hopes that someone will release a certain emulator in the near future, then I say it's not for you. The scene has a dedicated homebrew scene but it's hard for anything to move quickly.
Some of this has to be blamed on the whole open source ethos behind the device. Money makes the world go round so when there's no money to be made it's only the most dedicated developers who stay on a project. The community has been trying (several times) to organize a fundraiser for a programming contest in order to promote development on the device, but it hasn't materialized yet. Two things currently hold this up: 1) no one can agree on who should be trusted to hold onto the funds that are collected; 2) going back to emulation, there is a strong push among the programmers to get away from emulation and focus on homebrew. Of course, this doesn't resonate with a lot of users who bought the device for emulation and want to see certain emulators developed (PS1, N64, etc...) and feel the contest is a great way to finally get it done, so that causes a rift while they try to compromise and usually end up no where.
So back to my point, if you're buying it for the emulators it already has or you like the homebrew scene, then you're good.
In any discussion about the device it's impossible to avoid how badly the Kickstarter has turned into a fiasco, many people in Europe still don't have their units, almost a year and a half after it was funded. You won't have to worry about this if you buy through Thinkgeek as they seem to get all the units they need.
The biggest problem I see right now is the competing Android scene. Android is getting better and better by the day, it's very alive, loaded with new development and the game consoles that run it are getting better and better. Now that the Shield has dropped to $200, it really makes the case for the Zero a little more difficult. But, it's all up to you, there are plenty of options and however you decide, I think you'll be satisfied. Hope I helped.
