Pros
1. Good work life balance (workload is never crazy high and you can always work it out with your manager and team). 2. If you are looking for a stable job to pay your bills, it's a good company. But it's just that, good to pay bills.
Cons
1. Absolutely no growth career-wise and knowledge-wise. From my own experience, you will probably work on very mundane and uninteresting projects. (Atleast in the Mentor R&D, India). You will learn nothing new while working here. 2. There are too many unnecessary hierarchical position for the sake of it. So, it is possible you will be stuck at the same level for years with no possible growth in sight. 3. The pay is very low. The bonus and appraisals are also very demotivating, and there is absolutely nothing interesting financially. Basically you will not get satisfaction in terms of either your work or your salary. Personally, I feel these two are very important for a job tagged as "R&D".