I read the reviews and watched some videos before ordering this. It is heavy, sturdy and seems well made. I bought the more expensive model because I use larger than 1/2 in bits occasionally and it won't take long to pay for the upgrade at the replacement price of larger bits.
It takes a minute to figure out the process, the videos help a lot. I sharpened a lot of bits in about an hour on my first use. I even sharpened bits that were smaller than recommended by wrapping a piece of plastic sheet (cut from a plastic bag) around the small bits so they would tighten up in the collet. A little trial and error on the adjustments and bits look like new. I sharpened a few that had been broken and it worked just fine.
Use this machine in the garage or outside. It makes some dust that would ruin carpet and be tough on furniture. I have been sharpening bits for my kids. I would buy this again but I don't think I ever will need to. The only problem is it needs a latch to hold the lid shut. I am going to add one when I get done sharpening all my bits,