OUt my way Bamboo tablets run very high, but that is due to import tariff. I thought about them seriously before buying my Genius or INGenious. As they are for traditional art, I wonder how to make my drawings more life-like.
Bamboo, they're available in around A4 sized tablet, I've found it works pretty well. Mine is on the verge of breaking though, so I'm considering getting an intuos when it does because I'm sure that I want to keep drawing digital art. Bamboo is good for experimenting when you're just starting with digital but not sure. ^^
I think the Bamboo tablets are Wacom's budget tablets. I used to have an old "Graphire3" tablet from them that I got for around $100 (Graphire I think was the model that Bamboo replaced) and it worked just fine for what I did back then. It'd probably be fine for what I do now, too, as a matter of fact. It didn't have much surface area though, so that was my main reason for replacing it.
I've had an Intuos 4 for a few years now and I haven't had any complaints really with the tablet itself. Wacom software and drivers have been somewhat of another issue sometimes though, but still better than anyone else out there to my knowledge.
The more expensive the tablet, the more bells and whistles it'll have, and I'm not really sure how much I really need them since I'm not exactly creating masterpieces yet. I mean, my tablet was advertised as having something like a bajillion levels of pressure sensitivity or something, which I guess means it can make a cleaner stroke, but I never noticed much difference. It also came with a bunch of extra nibs like textured ones to simulate graphite/charcoal, regular plastic ones, soft ones for markers or something I guess, and a springy one for a paint brush feel. I've tried all of them, but for the most part I didn't really prefer any of them over the normal/black/plastic ones. The texture nibs seemed cool at first, but they wear down the surface of your tablet faster. This doesn't have any effect on the performance of the tablet that I've noticed, but the texture is less noticeable as it gets more worn, making such nibs somewhat pointless.
The best extra "bells and whistles" feature though are the buttons on the side. You can set them up how you want, (push this for brush tool, this for hand tool, etc.) which was cool at first. However, as someone who uses his tablet for school shit a lot, I'd end up having to set up these preferences every time I went to a different computer on campus. I gave up after awhile and decided to get used to the default settings or just use the keyboard.
The circle/wheel on this side is pretty cool too, and a godsend for someone who likes to rotate the canvas while they draw. The canvas rotation setting for it doesn't work in all programs though, unfortunately. I've only gotten it to work in the newer versions of Photoshop CS (CS5 and 6, possibly 2,3 & 4 as well but I haven't tried them. I know for a fact it doesn't work in CS1 and earlier though) as it seems to be tied to the canvas rotate tool (hotkey R in Photoshop I think?) which wasn't around in earlier versions and doesn't exist/work the same way in Corel Painter and GIMP. So it's kind of another one of those things that should only be a deciding factor based on what software you use with it.
Lastly, I have had some issues with newer Wacom drivers screwing up the pressure sensitivity in Photoshop, making it spotty. I'm not sure if it's Adobe or Wacom that caused this, and it didn't seem to be a problem for all users, but it was annoying and I had to rollback to an earlier driver.
TL;DR: the Intuos is nice, but it's more expensive and you may not end up utilizing most or all of its extra features. Depending on what software you're going to use with the tablet and if you think you'll end up using it with different computers a lot, the Bamboo may be the better choice.