Hi,
This is my small Intuous Draw Tablet you see in the image below.
Can I use this tablet for sculpting complex characters?
Any tablet will be far superior to sculpting with a mouse, as long as there is some degree of pressure sensitivity. From my experience, sculpting in zbrush doesn’t require the same amount of precision as, say, painting or drawing, so lower res or introductory tablet models should be adequate for most tasks. As you come to understand your own personal needs, you may or may not want to upgrade at some point.