Who said that? I've heard the opposite from Kontronik...

FWIW, I run a Jazz 40-6-18 on 4S in a 1:10 buggy. They work great, and the latest version 8 firmware has fixed one bug I used to experience, and improved the braking/reverse algorithm since version 7.

My BJ4WE has the Jazz setup right now. I was running it in my old RC10 when I posted some results of it. The beauty of the low voltage Jazzes is that they have a builtin switching BEC.

Well I've got a 1:8 conversion in the works, but haven't finished it yet. It's been months since I started it! Hopefully I'll get it finished soon so that I can post my experiences. I plan to run a Jazz 55-10-32 and a Neu 1912/1Y on 10S Lipo in it.