Honestly, the most I hear about the PayPal founders is when they get mentioned in financial articles -- e.g., "Today, PayPal founder Elon Musk announced that he's building a hyperloop to Alpha Centauri in the next 5 years...". But honestly, I've never seen them on campus or even heard them talked about that often. (Granted, I work from Omaha most of the time...but I think the same is true of most of our San Jose folks.)
Oh man, so hard to pin it down to one thing. First one: my managers. They're awesome people, and they're always supportive of everything I do. Anytime I run into an issue, I know they've got my back. Second: sabbaticals. Every 5 years, PayPal gives you a 4-week paid sabbatical. (Granted, I stayed home for my first one...but there's a lot of people that come back with some amazing stories about what they did.) Third one: In San Jose, soda is free. (In Omaha, 20oz bottles are $0.50, 12oz cans are $0.25.)
It's hard for me to decide. On the one hand, a lot of effort nowadays is going towards Braintree. On the other hand, I know that the PayPal stack has a lot of awesome solutions as well (hint: we have a lot of solutions that we don't advertise publicly). Bottom line, I'd say this: if you want to be able to do credit cards directly on your site, go with Braintree. They have some awesome JS code that automatically sends your buyers' CC info directly to them, so that you don't have to worry about it passing through your system. If you want the trust that comes with the PayPal checkout (or you don't care about taking credit cards directly on your site), go with PayPal.