Pros
I worked for St. Jude and got acquired by Abbott a few years back. The acquisition did not change the culture in the field, which in my experience has been full of superiors and colleagues who genuinely want to help you and do well. I am in the field and my job entails covering surgical cases and selling to physicians. The pay is great, and working with patients everyday gives meaning to your work. My manager has followed through on everything he promised me and always allowed me to lead the direction of my career. Abbott is a much bigger company than St. Jude, and you can tell that we now have more resources to drive business with things like R&D and marketing.
Cons
I've heard that not every territory is run the same and some are not as good as the one I work with. Also, since getting swallowed up by a larger company, there are a little more bureaucratic annoyances like constant online modules and more approvals for expensing certain things. But this is just because Abbott wants to make sure they are ethical.