the closest i have seen is art asylum on their website specifically the q&as they do, seems to me they are the only ones that care as much as scott even if the manager (that i cant remember the name of) has an unhealthy obsession with spiderman.
the marvel minimates line is the line that i compare most to motu simply because you get everything! not only that but they are redoing characters when their technology moves ahead.
even so there is a couple of differences:
number 1 being that it is a retail line while motu is online and that makes a huge difference! if motuc was at retail i could see more people picking up 2 or 3 of the same character as it is with the shipping etc it just isnt worth it
secondly motu as much as all of us would like to pretend otherwise gets so much stick whether its the filmation cartoon or some of the parodies over the years motu is taken as seriously as 1960s adam west batman!
now the motuc line is changing that with the amazing sculpts but for every micheal keaton and kevin conroy that we get george clooney and arnie come along to spoil our fun (sorry i saw the dark knight rises tonight and im in a batman mood!)