Most of them do. There are a few stores that I consider to have regular mall prices like PacSun but the majority do have outlet prices. The Disney outlet is usually 50% off the ticket price though you will find some special promotions at times. When I was there, they were offering $50 Tinkerbell and Mickey watches for $15.
Some of the best buys I found were in the Tumi store. Tumi makes high quality luggage and leather goods. I bought a $500 leather carryon/overnight bag for $175 and my DD bought a beautiful $400 handbag for $120.
If you sign up on the Prime Outlets website, you can print out a coupon for a free coupon booklet available at customer service. There aren't any coupons for the Disney outlet but there might be some others you can use.
When I was there at Christmas, there was still quite a bit of construction which made it difficult to walk to the Neiman Marcus outlet from the other outlets.
The Prime Outlets are not to be confused with the Premium Outlets which are the closest to WDW. The Prime are the old Belz outlets and they are located at the end of International Drive.