I used to use one - I find it annoying that my hand is in the way!
I have to say I prefer the normal Wacom I have 3 - Intuos 1 A4, Intuos 3 Special Edition A5 Wide and a Black Bamboo for the laptop - it only takes a day for most people to really get proficient with it.
I find artists that are new to digital often use them as they don't have to detach their hand/eye co-ordination, which seems weird at first but as I said only takes about a day of use before your brain adjusts.
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