Anyway, compression suits have been around for like 50 years.
Last time I checked (could be wrong about this, and correct me if I am wrong) Under Armor's products are not anti microbial meaning you have to wash them more often than companies that are. This leads to the product wearing down significantly faster. They do have a great marketing campaign though, and it tends to be the wealthier crowd that doesn't mind washing and wearing things out quickly.
Their suit isn't really anything new. If you are interested in compression technology, I recommend looking into Opedix http://www.opedix.com they have far more advanced technology, and all the items also have benifits like built in knee braces and shoulder support. More expensive, but much much much better for you.