My wife got me a Prime plus the dock back in May, and I've enjoyed it a great deal. Not quite a laptop replacement, but awfully close. I'd say a solid 90% of a laptop replacement... with at least 300% of the battery life.
The wifi isn't spectacular, but it's certainly acceptable. And while I've run into a few limitations (such as at one hotel, where I could hook up to the wifi but none of the browsers I had would authenticate to get out on the web) there haven't been any dealbreakers. I've been impressed with what it can do with games, and the screen plays movies beautifully.
I gather some people have had problems. But so far, it's been very nice. I'm really curious to see how it runs under Jellybean.