how long do they take getting use to?
It depends. I think for Skyrim it shouldn't be too long, a few hours maybe.
I used to play only on the PC, but about a year ago my frustration with PC crashes (I'm cursed that way) led me to buy a PS3. I love both FPS and RPG games and the FPS games were the biggest challenge to adapt to with the controller. It was made even worse because I used Killzone 2 as my first ever PS3 game. Now, after about a year's worth of (casual) gaming, I'm loving the controller. The experience of sitting back and enjoying a game, rather than sitting hunched over a keyboard and mouse is so much more fun for me. I've got only a few hours in Skyrim so far (about 10) and the controller works very nicely. Take care to customize the controls. I have found I use some buttons intuitively for certain actions such as spells, pushing the wrong button has gotten be killed a few times.