i actually have the memphis mc16-1000d. and let me tell you this little guy is one of my favorite amps i have ever owned. and yes its very efficient and gets very loud w/ great sq to back it up.
heres a list of amps ive owned and still own some of which im about to list. so believe me and you'll be satisfied w/ this amp. you make up your mind when you see my list.
Yea, like M.S. claims the Memphis 4 kilo-watt amplifiers have huge current draw and can use a new design so that they're not horribly inefficient anymore.