typing this on my phone, so it will probably be short and sweet.
1. The quality is good, yes, but most dslrs have one CMOS chip as apposed to the 3 CMOS or 3CCD's of most good video cameras. Thus, DSLR's will have less dynamic colors and are not able to pick up colors as accurately. The censors are smaller, so the lowlight performance is much worse.
2. Lens options are very limited. Yes, DSLRs have lots of lenses, but for filming scootering/skating, you need a fisheye, and DSLRs have very few fisheye options.
3. The audio is terrible. the stock mics on DSLRs are absolutely terrible. The audio sounds harsh and scratchy and you need magic lantern or something like it to get even acceptable quality audio.
4. Battery life. The battery life on DSLRs is horrible. Even with an extended battery the camera overheats and has to be shut off. I know t2i's are especially prone to overheating while filming for a long time.
5. Overall the comfort of filming with a DSLR is not good. They are not well balanced and they are very uncomfortable to hold and shaky when filming lines.
6. DSLRs lack a lot of setting that camcorders have, such as steady shot and ND Filters.
So overall when you get a DSLR the initial cost is only about half of what you will need to spend to get a decent setup. They are money pits.
Yes, fisheyes are not as readibly available as they are for camcorders. They are also much more expensive.
The audio on a DSLR compared to a lower end camcorder will be similar, but from my experience a camcorder MAY pick up less windnoise and experience less hiss when recording silence. Although the downfall with most inbuilt mics on camcorders that use tapes is, that the microphone may pick up the tape motor (At least from my experience). DSLR's have AGC (Auto Gain Control) which automatically adjusts the microphones audio levels depending on how much sound is being picked up. Magic Lantern disables this and is also able to be disabled in the Canon 60ds latest firmware.
From my experience, my camcorder battery only used to last about 2 hours due to how old and used it was. My camcorder btw was just a canon MV800i. Other batteries would last longer, I know. My 60d battery lasts easily a day of shooting but the more you use and recharge batteries the shorter their life becomes. And of course, when you are recording video the battery dies faster. As well as shooting in cooler conditions. And yes they do overheat if you film for too long. But this really shouldn't worry you. You also can only film for 12 minutes until recording has stopped on a DSLR.
I agree, filming with a dslr is ALOT harder than with a camcorder. That's why there are many rigs out there to film with. Focus is also an issue because most DSLRs that shoot video do not autofocus during recording. It is full manual focus. Filming lines is ALOT harder than with a camcorder of any sort.
I'm not sure what you mean by ND filters, because you can certainly get ND filters for DSLR's that screw onto the lens. And yes steadyshot is not an option imbedded into the actual camera itself but certain lenses do have IS/VC/VR which is basically the same thing.
The main reason people use DSLRs is the wonderful bokeh that is able to be achieved by using a DSLR, which cannot be achieved with camcorders under around $50,000. But if your looking to get really artsy and are willing to spend more than you think you will. Get a DSLR for filming.
PS - I think the OP was wanting this for stills. Is this true or were you wondering about stills and video?
