I've tried the 25A sabertooth, many electronize and the sidewinder (bit over rated for a feather). The one I would recommend would be the electronize. As others have said, solid little controllers (can handle inrush currents into the 100A+ mark) so they are well rated for drill motors. I had issues running the sabertooth to it's limits and the sidewinder was nice but at 400g or so too heavy.

I have never noticed a problem with accuracy of the controllers. I'm always of the opinion that if you can't control your machine with something like an electronize then you have more issues than just the speed controller.