There's a lot to agree with in all the above posts, and as a Dremel (mains) user, and a user of one the Workzone (Aldi cheapo "Dremel knock off") my own experience reflects most of the above comments.
Re the Dremel, mine is over 15 years old now and gets LOTS of use for all sorts of things. So far, never one moment problem. The Workzone is clearly a cheapo, and right from the start had noisier bearings than the Dremel, but after at least a couple of years heavy use it's also still going strong - though no doubt one fine day I'll have to strip it and replace the bearings with SKFCO or something decent. From the looks of things that won't be a huge job.
I've also heard on here that Dremel quality isn't what it was, especially on their battery tools (which I don't have). And that's maybe because their tools are now made in China.
As I've said before, personally I don't believe that "made in China" (or anywhere else for that matter) necessarily means carp. IF the OEM is subcontracting his own designs to a Chinese factory, provided the OEM maintains oversight on materials and fasteners specs, manufacturing tolerances, and correct assembly, there's no reason why something from China cannot be every bit as good as the "same thing" from somewhere else. Some OEMs clearly do care about quality, some "not quite so much"!
Re carving, I'm definitely NOT much of an expert (I don't seem to have the "eye" for it), but I have been experimenting with 3D/compound cutting on both my scroll saw and my band saw recently (see the pic from Robbo 3 above.
Nice though such things do look, you'll notice that these animals have "square edges" - something that real animals don't often suffer from!
So I've been using both the above "mini drills" with and without a flexi shaft to try and "improve" the look of my cut out figures. BTW, I've also used a sharp knife, a small sharp chisel, plus various bits of sandpaper wrapped around formers, finger nail emery boards, and various "Dremel type" sanding cylinder/drums ranging from about 6 to 20 mm dia. It all works.
But I've found that all "motorised" shaping takes a bit of getting used to, and if not careful (it seems I wasn't!) you can soon end up with a cat without a tail or a dog with only 3 legs or 1 ear! "Practice makes perfect" - as is so often the case!
But neither drill seems to suffer from the side-loading of the bearings (when used without the flexi shaft), and holding the "handle" of the flexi shaft is anyway a bit easier than holding the drill itself right down near the chuck/collet.
About the only thing I've found with a flexi shaft is that even if you follow the Instructions and do NOT allow the shaft to tie itself in a knot (just allow it to make a single gentle curve) it does run a bit warm after a while. I have 2 of these flexi shafts (one Dremel, one Workzone) and every so often remove the inner and run along the wire spiral through my hand with a little Vaseline on my fingers). Seems to work OK. I've also found the clamped-on vertical hanging post (that came with the Workzone kit) very useful to keep the drill itself out of the way of the job.
BTW, I DO also have a horizontal fixture for a (mains) electric drill and use a somewhat larger (dia) flexi shaft with that. But for that I use a set of mounted stones of various grades and shapes (cone, cylinder, drum, sphere, etc) but so far ONLY on bits of metal (the stones I have are NOT suitable for wood anyway).
Apart from their "Kwik Click" attachment for mounting thin cut off discs, I don't use Dremel's proprietory accessories at all. There's loads in the Dremel catalogue, but compared to others which seem to be freely available (e.g. the set that came with my Workzone kit), Dremel's don't seem to be of any better quality and are much more expensive. If you do go this route I'd suggest keep your eye open in Aldi and Lidl, and also in the "cheapo rubbish bins" you often see in DIY Emporia. I've picked up all sorts of such cheapo but useful "junk" in such outlets.
And agree 100% with buying tungsten carbide "dental burrs" from China. MUCH cheaper and just as good as (better?) than Dremel's own which are again, rather expensive.
Just to be clear, we are NOT talking about producing life-size sculptures here! For that you'll probably need something like Arbortech (which uses an angle grinder as power source anyway, NOT a "Dremel").
Finally, based on the design by a very well-respected member of the Scroll Sawing section here, if you're going to do much of this, especially "powered carving & sanding", then IMO you need some Dust Extraction.
Brian's idea was simple. Buy a decent-sized plastic washing up bowl (choose an oval one, not a round one like I did!) drill a hole in the bottom to take a suitably-sized piece of plastic pipe and a sieve with a flange (for a sink or something), to fix to the bowl. Connect a shop vac to the underside of the pipe, set the bowl between your knees and carve/sand away with the vac running, holding the job over the bowl. Mine works fine and clears most of the dust (but I DO wish I'd chosen an oval bowl)
HTH