For me the preference is full featured for a short time which then automatically disables some features and goes into "free" mode or at least "I'm going to irritate you untill you get your wallet out" mode.

There is plenty of software which is free for casual users but charges for those who want a bit more advanced functionality and/or support. I don't want to pay £100 for what could well be a great piece of software but has functionality which I may only use for a couple of hours a year.

(I'm currently in that dilema with XML editors, I want something with enough features but they all seem way too expensive for the amount of time I'd actually use them for)

Personally, I think its a great way of expanding a products user base, especially with modern software and systems there are always going to be bugs that get past testing. So the more users you have, the more chance you have of finding those bugs quickly and getting updates out.