I think like most things you get what you pay for. I have some Veritas ones which are very good, some Trend ones which are okay and some unbranded ones which are rubbish.
they do vary. I have had an unbranded one and the veritas tapered one and the difference is night and day. IIRC the Fisch got very good reviews in the past when somebody asked a similar question
They all burn if the speed is too high. The best I've found are the tungsten tipped cutters from www.wealdentool.com.
However, the Veritas tapered cutters give a very snug fit with no gaps but are a little tricky to use as the hole must match the mid-diameter of the cutter.