Great for a few years, tought on the long run.
Pros
Working with loads of smart people is great, you learn a lot. Benefits & perks are good.
Cons
Over time there's this pressure to over perform beyond your level, with removal of bonus: there's the expectation that you should always be delivering more and more, to get the same bonus. This becomes unhearthy, as work and life balance suffers, pressure increases and you end up receiving less compensation for what's essentially the same work. Also, there's a MASSIVE disconnect between "everything proprietary internal" and "the real world", so the longer you work for the company, the more distant you are from skills and tools that'll use at your next job, as most of what was learned, is essentially lost. Stocks compensation also decreases with time, which is another driver to "only stay a few years".