I have a simplified explenation towards the whole Max and Maya issue here goes: Maya has alway's been a highend program, Max is crawling its way up to the highend but they have small bugs to work out (what program dosn't?) I use both Max 6.0 and Maya 6.0 here are some advanteges for each one.

Maya to Max: Maya can have much more in a scene before the response of camera movement is slowed down, when you start pushing 10k poly's in a max scene if you have a p4 1.8 Ghz pc, youl start slowing down a bit, but Maya will keep you runnin smooth

Maya to Max: Max is much more widely used in architecture, infact I havnt seen any compagnies use Maya for it (altough I bet there are many) but they prefer MAx, Viz and Auto-cad (which means Discreet owns that field)

Maya to Max final: if you look at new features in Max youl notice they are just comparing to Maya 5....

hope this helps