All I can say positive about Epco is that they have a great selection of paint and supplies. However, the real reason people tend to go to more expensive, smaller (non-big box) stores is the customer service. Theirs is awful. My wife and I ordered a Hunter Douglas treatment from Epco in June; it's August and it's still not up. They only sell Hunter Douglas in window treatments, so we felt they'd probably know their stuff. The saleswoman in the store doesn't do anything but read what the catalogs say to you (I can read, thanks). She doesn't recommend anything in terms of solutions to more atypical window treatment situations. They have an installer come and do the installation and measuring for you for a fee that is refunded if you spend over $500. The measurements the guy took were wrong, and we had him take them so that any error rested on his shoulders and not ours. Sure enough, the treatment wouldn't fit, and every excuse in the book is being thrown upon us, and we've even had lies made up saying we told them to order it at the wrong size. This place is anything but professional. Plus, at the South Elgin location, I'm unsure how they stay open, as the dozen or so times I've been in (on weekends, because their weekday hours don't suit the working public), there's been no one else in the store. Hopefully the place will dry up and they'll be forced to close. I won't miss them. They sell Benjamin Moore paint, but you can get that at Ace Hardware. I'd suggest going there instead.
Pros: Variety of high-end products
Cons: Non-existent and unprofessional customer service