I like mine a lot. Since Saturday, it has hardly left my hand. The things I don't like about it are the obvious: no multitasking(can't use iheartradio while surfing the net), the constant safari page refresh, and the wifi drops a few times a day.
Out of those three things, I have to say that the page refresh issue is the biggest I-don't-like. It wasn't such a big deal at first, but it has become rather annoying to go to another tab for less than 30 seconds to find that the original tab I was looking at had to be refreshed. This happens with only 2 tabs open. I've tried clearing the cache and history, rebooting, but it doesn't help.
The wifi issue is not really that big of a deal for me. When the connection drops, it reconnects rather quickly with no input needed from me. This happens a few times a day.
Finally, my smallest gripe is the multitasking thing. The reason that it is not so much of a deal is that I've never had it before and have gotten used to being able to use only one app at a time with the iphone. Not to mention, Apple has already addressed that problem with 4.0. Though apps that stream audio are pretty much worthless at this point.
Those are the gripes. The things I like about it are:
the portability, awesome screen, netflix, and it's fun to use.
I can take it to the crapper with me

It goes from the bed to the living room without having to unplug wires. The battery life is phenomenal.
The screen is absolutely awesome. It's just the right size for reading, watching videos, or playing games.
Netflix is the best app ever!
If I was going to do it over, and had the choice right now of getting the 3g or the wifi, I really think I would still have gotten the 32gb wifi as I did. My iphone will be sufficient for tethering when I feel the need. Also, I did a little test yesterday. I ran speedtest while tethered to my iphone. The speeds were luke warm to say the least. I got 500 down, 100 or so up. Then I ran speedtest on my iphone while connected to 3g and got the same results. So it wasn't mywi that was slowing it down, it was the 3g that was, well, just slow. And that made me wonder if I would really get more use out of the 3g model, rather than the wifi. With the connection I tested, it would not have been ideal for streaming video at all. I don't know if I could justify the extra cost without being able to take full advantage of the device while on 3g.
So to sum it up, I'm happy with what I have.