Pros
With the industry still contracting (ie Merck's recent layoffs) it is comforting to have peace of mind that we should be secure for the next few years with our recent success. Fun environment (lots of parties), great benefits (stock options are a huge plus even for those of us in lower positions), above average 401K and insurance, tuition reimbursement even increased. With recent success, salary is catching up to industry norms, I started ~4 years ago and felt fairly underpaid at the time, especially considering the cost of living, but since then the compensation has improved where I no longer consider it a con and it was a huge one to start.
Cons
Unclear direction for growth/advancement. RA's (non-Phds) generally have a rather define glass ceiling (RA V). In my group, not a lot of distinction between the levels (RA II vs RA V). Promotions are difficult to obtain. Position can be monotonous and unchallenging after time again due to lack of growth and increased roles/responsibilities.