Probably non-existent at the PE stage.
It also varies within firms -- it's down to the individual partner -- but the overall firm matters too (or else "your" partner gets blocked on doing helpful things).
The best strategy, IMO, is to get an early investor on your side who shares a lot of the same goals (e.g. YC), and then work with the early investor to find later stage investors who are compatible.
(There's one specific firm and one specific partner I really like, but I haven't taken investment from them, so I'm reluctant to name. I get better advice from him/them already than I'd expect from an actual investor, though.)
For my part I have an mental list of both vc's I'd love to work with again, and VC's I not only will never, ever take anything from again even if it's just a free pen, and while I won't badmouth them publicly, there are certainly some I like to think I will slide just a little bit quicker into obscurity thanks to the odd situations where their name might have come up in conversation..