Vantaggi
There is a lot of good going on at Red Hat - they have their hands in a lot of awesome enterprise open source projects, and have a very interesting place in the industry. For better or for worse, the culture is very open - no one is afraid to speak their mind, and the CEO actually responds to communication from individual contributors. Compensation and benefits are very fair, IMO - certainly not the best in the industry, but I have no complaints.
Svantaggi
Linux subscription growth is slowing, and customers aren't as afraid to go it alone without vendor support, after seening the Amazon, Googles, and Facebooks of the world do everything in house. Ansible and OpenShift are the big drivers at this point, and if you're not tied to one of those products, you'll feel like you're not that important. The openess I mentioned as a pro can be a bit of a negative at times - sometimes you get streams of consciousness from product management about road map items without fully thought out messaging, which will scare the sales staff away from a particular produt. There can be a cult-like mentality at times - some associates believe Red Hat can do no wrong because open source is inherentlly good, and proprietary software is therefore evil.