I bought a couple of different cheap consumer grade video cameras for about $300 (Sony & Canon). I hated both and returned them. Couldn't even turn off the auto focus feature.
DSLR's with video capability, such as the T3i-T4i-T5i, and the 60D or 70D put out stunning video- video that looks like high end cinema. I know much of this is due to the skill of the photographer in shooting & in post processing, but nonetheless, they look incredible. You would need professional lighting especially if you plan to produce the videos indoors. If it were me, I would look for a standalone prosumer-grade video camera to purchase.
The limitations I hear about tend to be with regard to certain shooting limitations, like with some DSLR's, you can only shoot 30 minutes or so at a time, and that the ergonomics aren't as nice, and some can heat up when shooting for prolonged periods.
But, if you shoot short youtube videos, they can look unbelievable. Shooting a feature length film can be challenging, but can also come out great if you know what you're doing.
The problem with autofocus on moving subjects has been addressed with the new focus system on the 70D- it can focus quietly and quickly on moving subjects with very good accuracy. Check out some videos for examples- just go to youtube and look up 70D video- I've seen some that look amazing. I'm starting to think my next camera will be a 70D for this reason. Unless they come out with something better that's in a price range I can pay.
But, it all depends on what kind of video you want to shoot. many youtube videos could just be shot with an iPhone. It all depends on the subject matter, and the aesthetics you are going for.
I've had my Nikon D70 for almost a decade. Still does fine, except I want video as well. Saw the sale sign at a local camera shop. The salesman claimed the D7100 is right for me as it's mid-level (since I'm migrating from a D70, I shouldn't step in the beginner SLR). I wanted a Nikon since I already had Nikon lenses, but was told my old lenses are crap and need to be upgraded. So if I have to get new lenses, I don't have to stay with Nikon.
I take lots of pics for selling stuff on the net. I usually take 50 pictures of each item. I really like the newer camera's with HDMI output so I can instantly see the results on a monitor. I also make some basic YouTube videos and hence want video functionality. Some outdoor photography while hiking.
He showed me the D7100 w/18-105mm lens for $1,400. It's priced similarly all over the net (it's the authorized Nikon price). Before buying this, thought I'd ask the experts. I haven't followed camera technology since I bought my D70, so I'm lost. What would you buy for $1,500 (camera and one quality lens)? Nikon, Olympus, Sony, Canon, etc? If you know of a really good deal somewhere, it's ok if it exceeds $1,500, but not by much.
Photography-wise, if you want quality results, get quality lens. That's where you'll see the most improvement. I'm not saying that you shouldn't upgrade the body or that it's unimportant - certainly it does factor in, but rather, it's less critical to getting quality awe-inspiring shots. If that makes sense?
Batteries die and memory cards run out inevitably right in the middle of a scene. Many DSLRs and mirrorless cameras have to be removed from a tripod before batteries can be replaced. If filming a commercial where I can say "cut" when my batteries run out, fine. But if you're filming live action...get a video camera.
