Some initial impressions (got mine on 6/6 — base and extra controller, in one box):
The WiFi on it is pretty poor. I moved it around a bit to get better reception. Makes no sense, as I have other devices in the exact same area which work perfectly. It’s 2012. I shouldn’t have to pull a CAT5 cable through my house.
Store is slow, slow, slow. Again, I hope this is growing pains. Downloads take forever and screen refreshes, too (the thumbnails). Sounds like they need more servers and bandwidth.
Flaky controllers: When I first started playing, they seemed fine, now they have intermittent fits. Ghost clicks and slow response (try playing pinball). Happens in game and in the menus.
I get forgetful sometimes: After a restart it sometimes forgets the paired controllers, so you go through that process again. (Now, the pairing process is painless, but forgetting controllers is a drag.)
Firmware: Get your network and controllers all configured, then it needs a firmware update, at which point it forgets your network and controllers. That’s sloppy.
Games: Early days. But no assortment of puzzles? Give me at least one Bust A Move or Fruit Matching ripoff game! One car racing game that I can’t figure out how to start?
For Developers: Please, please, please display the controller mappings! On most of the games I have to mash buttons to figure out what does what.
On the bright side, I like the controllers (when they work), and the console is fine. A 6′ HDMI cable would have been appreciated, but at least they include one (4′). Some of the games are nice to see on a big screen. You Don’t Know Jack looks beautiful (but $10) — very polished.
Based on some of the games I’ve seen, the machine has a lot of potential. Let’s hope that upcoming firmware updates fix the above issues. But, right now, it’s BETA at best.