I have an A4 Nisis that I never use because it is way too big and the sensitivity settings don't really work. I got a 6 by 4 Wacom for Christmas and it is wonderful. I'd recommend a smaller working area as it is plenty big enough to do detailed work with and it fits in a laptop bag. I'd recommend a Wacom because they are great - and the pens (at least on the graphire) don't need batteries. There are also a lot of them floating around on ebay and they don't seem to suffer from wear and tear so they seem to be a good thing to pick up.