The only drawback to these (we’ve used one exclusively for years, we actually have two) is that they need the mildly aluminized paper discs for the bottom. I don’t fear the aluminum, but they do cost money, they’ll run you about 50 cents each minimum, they’re not easy to find cheap online – I do pick them up at WalMart when I can’t find them online for cheap. You can get two uses out of them sometimes.
We tried a NordicWare which is like a ceramic-looking plastic that doesn’t use inserts, but it wasn’t nearly up to the standard. We use that as a bowl now, if we still have it.