when I first got my Nokia770 I started right away with hacking (developing and porting applications) rather then actually using it. I started being just a user over the Thanksgiving weekend. Some user things I noticed where:
We have Flash/Shockwave support, thats kind of nice. I actually didn't expect this. Also web browsing is really nice, just sitting on the couch watching TV and surfing on the tablet. But unfortunately the browser (Opera) is sometimes a little picky and crashes or just eats memory when going to some of my favorite sites.
A PDF reader, yes there is one on the 770. Don't reading the product manual really pays of - if you like surprises :)
Now for some bad things, the email client. I think I remember somebody complaining about the lack of SMTPS (SMTP with SSL) support. Yes, this is unbelievable the email client doesn't support SSL for outgoing mail, why? This makes the mail client totally useless and just a waste of storage space. Maybe the idea behind the email client is a email reader because IMAP supports SSL. Anyway Opera nicely renders my webmail page (IMP/Horde), so it's not to bad.
Some remarks about the filemanager, especially about the OBEX browser (this is the thing that gives you access to the files on your phone). The OBEX part is supper aggressive, it not only gets the current directory information it also goes into subdirectories. If you browse directories with a lot of subdirectories and files, the filemanager sometimes is just blocked totally because of all the pre-fetching.
Also you can't directly use files from OBEX sources, I wanted to play a MP3 from my phone on my 770 but the audio player complains. I thought I could just use the big SD card in my phone as network storage for my 770, but I guess I have to finally finish btfs to get this functionality.
One last thing, I noticed that the wireless antenna (802.11/WiFi) seems to be pretty good for such a small device.