My husband is fairly amazed at the intensity with which clay grabbed me. We were in the shop doing a kiln repair, 11:00 at night, 20 below outside and not terribly warm inside, and I said, "I bet you wish I had have been a knitter!" And he said "Oh, that wouldn't have been nearly as much fun!" And he meant it.
I have a tabletop Northstar. I absolutely love it, but......I have never used anything else, Well, I guess I did use an old Bailey that wasn't in that great of condition......but yeah, I use that Northstar all the time. No metal flakes. And yes I bought it new. It arrived with a broken shelf and Northstar was so nice to replace it. Perhaps just give them a call.
Because of Old Lady I have crossed over to the "printer blanket" side of life. I love them! I use the canvas only for a few things that I want that canvas texture. Yep call your local newspaper and you can get them for free and cut them to the size you need. I also use the printer blankets for wedging.
Stephenw, I have rebisqued pieces because of getting wax in the wrong place or some such thing. I have not had a problem with rebisquing. I also usually bisque to 04.
In my personal experience, I have tried certain manufacturer's clays that simply did not work with my glazes. That was where I seemed to have the most problem with pitting. The other reasons are 1. I didn't wipe the pot off carefully before I glazed 2. The kiln was not fired properly (hot enough) for the glaze firing. I usually add a 10 minute or more hold at the top for the glaze firing. Many people have recommended a slow cool as well. 3. the glaze and clay simply do not fit.
There are others on this forum who have much more experience than I do, so maybe they would have other suggestions.