that may depend on your definition of full use tablet. Around here we describe things as tablet pc for those with full operating systems that use digital inking and can run regular software. some tablets that are just tablets are more entertainment oriented, but can do some inking and functions. So the real question you might need to ask is what do I want this 'tablet' to do?
Please note I don't have a kindle fire, this is merely from reading reviews. The only observation I have about the kindle fire is that it doesn't really seem to have a lot of editing capabilities for documents and pdf- this might be limited. It appears geared toward an entertainment hulu etc movies and ebooks and emagazines. You can read pdf, but you'll have to look up to find out how much annotating and note taking you can do.
Again, the question to ask yourself just might be what to I need a tablet to do and what do I also want it to do.
TC1000 tc1100 tc4200 and now a tc4400