Well the maya particle system is far more roboust than the max sytem so most of this kind of stuff can be done wiht expressions. or directly trough the api... but iill read a bit more
i havent used the system but what exacly does it do that expressions cant do? Ok some of the stuff can be tedious work like fragmentation but.
and pyro clusters isnt available. and then offcourse the instances sucks (maybe one could do a perticle copier?)
id say the biggest reason for theese kinds of stuff not being so common si tha fact that the maya sytem is more closed... and better so you dont need so much more stuff.
but hey if you neoticed thinking particles costs nearly as much as maya complete so...