Pros
Great company culture. The company will do a lot to encourage your professional development as an individual , not only in the light of staying with PayPal. There is a great family spirit there, management is very relaxed in terms of where you work from and working hours, fantastic extras such as a fridge full of food for those days when you can't go and get lunch. The offices are generally in great locations, the UK one is in Richmond, right by the river.
Cons
The company has grown and has gone through a lot of changes , at times there was a bit of destabilisation with 4 reorgs in 3 years. At times, you might struggle to progress due to a headcount freeze but they are open to offering a transfer to another team in case you get bored of the job.