well i can answer 3 out of 4 of you question. is it legal?, new motors that blow those out of the water?, what I have still competitive? depends.

if your just club race hopping, even a few "big trophy races" or "what". you'll be fine and more then competitive with what you got.

if your one of the few that are the top echelon of drivers following the pro circuits, then yes there are faster an far more competitive Motors. and just about ever current generation motor should blow 2-3 generation old motors out the water. As governing standards are loosened, and engineering brake throws are made.

now which ones the fastest for your application?... Thats a good question.

esc well i sold my sole to Tekin. no real good reason why. HW stuff is very very popular at the track i run at. be on that as long as your esc aren't glitchly or 2 gens old i wouldn't worrier. but there has been some changes bout nothing i would consider "GROUND BRAKING" be on being 1 gen old.

my 2 cents