No, it wasn't just a parts swap. It was a redesign of the board with a new chip and for some reason the new Fet. Looking back I've got gerbers for the original board, but no schematic.
So the question is, can I find a fet that will drop in and allow better operation like the one I listed above? Or am I better off just leaving them as is with the 355? If I can get better performance with a new Fet, that's what I'm after. I'm not looking to do a board redesign or anything.
It's not worth the effort of putting a lot of time into, but if I could make it perform better with a different drop in fet, then I'd try it..
Thanks for the help thus far.