Most artists I see use some model of the Wacom Intous series. Small tablets work pretty ok for 3D sculpting I think - I currently only have an old small Wacom Bamboo that has served me well, but then I haven't done a lot of 3D modelling for the last couple of years. Most artists I've seen at my studio have something like a medium or large Intous.
I think for drawing specifially, I have used a small Wacom Bamboo for drawing. I wouldn't recommend it but it works once you get used to only drawing with your wrist and making small motions. I am personally looking to upgrade to something bigger for my own personal drawing after having had an bamboo for five years.
The only benefit with a small tablet except for the price is if you have a small desk, or are looking to bring it with you when travelling. It's very easy to fit in a bag. So there's that I guess.