That is VERY opnion based question.
powerfull- compare to what? what are you comparing it to? if your comparing to a .15 its extremely powerful if your comparing it to a .91 its not worth poop.

quite- what the h*ll do you mean by that? Like is quite tv volum quite like old car running? what do you defin as quite? were are you flying? if your flying over you neghbors it wont be quite enough anf for that fact no glow motor will be.

AS i said erlier if you need all out sound less operation go for an electric. im sure you could google search db volums for the engine evan i bet you could email tunder tiger and get them to tell you.