I really like my MPX...It does, however, have a ton of upgrades to it but it works for me.
MPX is an awesome gun (Sig is on a roll lately with one homerun after another). A bit $$ for my range though.
as much as a sig fan boy as I am, I doubt i'd ever buy a mpx, not that theres any problem with them, they're just too damn expensive!
The MPX was high on my list after seeing them at the NRA convention here in Indy.
The price is definitely what pushed me in other directions and why I went with the FX-9 as my initial and very simple step into a PDW as I already owned Glock mags, etc. Overall the MPX seems like a slick gun and would be in my safe if cost wasn't a factor.