yes, I find it useful. It's by far the biggest of the genealogy sites and has lots of stuff that the others don't. Of course if it's stuff you don't actually want, that's not much help. But I need non-British details, and it's good with worldwide families; I also need stuff from before 1837, when official registration began. It's pretty good with 18th-century parish records and so on.
Searching under Family Trees is often a good idea as people who know their families well provide details not available anywhere else. (Others of course just upload rubbish without checking.)