I bought one of those Maxiglide things and reviewed it here a couple of years ago. I had exactly the same experience you did--I had the feeling it was going to rip hair, and it did. I sent it back to the vendor with some suggestions for improvement, like taking the little ball off the end of the teeth and making them smooth with a more graduated shape, and making a smaller version for more control and to get closer to the scalp, esp for shorter hair. Guess my opinion wasn't as important as they would have had me think.
There was no way I could see myself using that thing every day b/c I straighten every day. It made my hair full and swingy, but that ripping issue....
Go for the flat iron--they even have some that are curved so you don't get such a flat, stick straight look that you then have to turn around and curl again. CurlMaster makes one. Good luck.