Pros
Salesforce deeply cares about it's employees, closely followed by it's care for "Trust": the idea that customers can expect their data to be secure and available. I work with a bunch of smart people that care about each-other and our customers, and even though there are over 16,000 employees, I generally feel like I work at a small company. I have insight into product direction and how things are going financially, I have impact on who we hire and who I work with, and I get to see immediate value from the work I put in. Salesforce gives me all the tools and resources that I need to do my job, and any time I've needed help from HR or IT, the big company pros are there. Salesforce want's me to spend my entire career here, and what I initially thought would just be a few years looks like it could be a lot longer.
Cons
It is a big company, and knowledge transfer is always tricky. I suspect that there is a bit of duplicity that goes on in engineering, and there are definitely things that parts of the business have learned that other parts of the business could be greatly benefited from but don't know anything about.