is this considered the most powerful brushless motor..

[lincpimp]

A 1521 1y is a good step up for a heavier vehicle over a 1515, something that you want to gear faster than 40-45 or something with very heavy tires/wheels. I run 2 of them, 1 in a muggy and the other in a lst. Both on 6s, both geared for 45. Good motor temps, even on 95+ days.

I will say that the 1515 1t (cc2200) is a great motor for 5s, if you can gear it down to reasonable speeds. I ran a lst with this motor on 5s geared for 42 or so with truggy tires. Did very well.