I also wish they hadn't limited the internet use on the PW. I was considering updating to the PW 3G, but the limited web access is a little disappointing.
I've never tried to tether my current Kindle (Keyboard 3G), but I do use it to read on fanfiction.net when I'm on the train or the bus. I mean, I can use programs like FLAG and Calibre to upload stories, but for fics that are still in progress, it's always made more sense to simply bookmark the last chapter available and check up on it later. It also takes up less space on the Kindle.
Maybe that's still considered an abuse of the web browsing feature? I don't know.
I'm very attracted to the overall sleekness of the PW, but the Keyboard still feels more useful for my purposes.