Pros
The best reasons to work for Capital One are the work life balance and flexibility to perform your job. No set hours and you aren't tied to your desk. As long as you are performing your job well, you have the flexibility to set your own schedule and work location flexibility. This is a huge advantage compared to other companies I've worked for in the past.
Cons
The performance management system is a bit frustrating primarily because you don't really have any set performance goals that would give you a guaranteed rating. You are judged in a pool with your peers on a bell curve. If a peer gets a high profile project to work on and you don't, they will likely get a higher rating even if you produced more results of equal quality. Likely similar to a consultant environment minus an up or out philosophy due to it taking longer for promotions on average. Just recently modified job levels to increase opportunities and shorter times for promotions, so they are trying to improve the system. However, they need to work on helping to adjust management's mindset to align with the new system as many of them still have the same mindset based on the prior longer promotion process.