I have a Little Giant 2-MDQ-SC (but I don't have a waterblock

).
Similar rating to the RLT20, but rated at >180 Watts. I should mention that it's a hybrid direct-drive/mag-drive (a motor drives a set of magnets, which in turn drive the impeller) so it's probably hard to compare it straight with another pump.
I picked it up at a flea market for $40.00