Pros
It pays well. There are some people who work there who are genuinely talented, cool, and fun to hang out with.
Cons
Much has been said on this website, and much of it is accurate. I don't want to write a long review re-hashing all of that, but I do want to call attention to the validity of some of the other reviews here on Glassdoor. The assertion of the review submitted on 10/31/2014 ("Don't believe the positive reviews - IT'S A SCAM!") is accurate; I personally have talked to a few team leads who stated that they had been pushed by upper management to write a positive review on this site. While I believe that the "Pros" section in their reviews was largely genuine, I am strongly inclined to think that their incentive was to pull punches in the "Cons" section and in the overall company rating. I can also see one or two reviews that look fake to me, but I couldn't prove it. If you take away these reviews, then Unlimited Systems would come out with a much lower overall rating than it currently has (2.5/5). Do you really want to work for a company that has to cheat on its Glassdoor reviews?