Pros
The pros are hard to think of. The health insurance was good. The location and office space are both pluses. Other than that it's fairly hard to come up with pros. Um... The research infrastructure is good. Weighted midpoint prices are a nice quantitative innovation.
Cons
XR (which stands for "Ex Rho Trading") has got to have the most incompetent management team in prop trading. The talent left between 2009 and 2012. The architecture has some serious flaws and the people available to fix it are long gone. The bonus system is a sort of sick joke. The owner of the company is still being sued in the Law Division of Cook County by one of XR's founders. There's a really low salary cap and your 6 month bonus is based on impossible goals and you'll never receive an entire bonus because of their "hold back" payment plan, plus it's really bonuses every 7 to 8 months. The cons can go on and on...