I pay £120 a year, I used to be a bit doubtful as to the value but recently the data searching facilities seem to have become a great deal better, the 'hints' you get tend to be pretty good IME. But best of all is being able to hook in to other people's trees. I seem to have eventually tracked down my great-great-great grandfather, he was an 18C peasant in Shabbington, near Aylesbury and was recorded as a pauper, so no long-forgotten family fortune for me...
Every year I think about cancelling, but then before I've got round to doing anything about it I get an email telling me they've taken the payment for another year, so it goes on. If I did ever decide to quit I'd make sure I did a full export of the tree (it uses GEDCOM format like everyone else) and I keep all the photos and documents on my personal cloud as well as theirs.