They are,
the 2650 is 1512 size, and thats around 2500kv :P I think its basically made as a 4s buggy motor. Thats certainly my plan for it anyway lol A hair under 40k on 4s, and a hair under 50k on 5s - would be good for both I'd say. I heard somewhere that in general neus have their super efficiency up to just over 50k rpm.