I have one J. Press sack suit from the "Pressidential" line and one from the "Pressclusive." You'll find a lot more detail on the differences between the various lines by searching old threads. Here are just my personal impressions:
Pressclusive: Made by S. Cohen in Canada. I really like S. Cohen's stuff, some people here don't. Suit is slightly shouldery. Still pretty natural shoulder, just not as good as some of my Southwick suits. Overall very decent quality. An excellent buy from the price- at least as good or better than most of what you find at Nordstrom today. An excellent "utillity player."
Pressidential: Hard to really describe, other than it's like the difference between riding in a nice Caddy and in a Rolls Royce. You can just tell by the look and drape of the fabric, this is a nice suit.
I also own a Presstige sport coat (also Made in USA), and the overall fit and quality of this jacket is pretty close to the Pressidential. So if both are in your price range I wouldn't worry too much between Presstige or Pressidential, and I would just pick the color/pattern you like best.