(disclaimer: I used to work for EMS)
AIt really depends on what you're getting. Someone else mentioned the Summit Gore-Tex boot.. which used to be handcrafted in Italy and was fantastic. Last year they moved production to China and they really suck now.
For the most part, the outerwear quality is as high as anything else on the market. There are some EMS brand products that aren't that great (the socks kinda suck), but for the most part the stuff is great... often getting produced in the same factories as stuff like The North Face. A lot of the product design could be better, IMO, but I can say that of any manufacturer (hmm.. except maybe Patagonia
And the guarantee is fantastic. You can bring anything back, ever, and if you're actually unhappy with it for any reason they'll replace it, repair it, or (if you have a receipt) hand you cash back.