My nephew went to Princes Risborough , as have a few friends children and I know someone who taught there.
It was not over-subscribed this year; the only other school in the area that wasn't was Mandeville, make of that what you will.
It's OK from what I hear, not one I would have chosen though.
I live in Aylesbury so didn't stand much chance of Lord Williams (my daughter has just started Y7 so went through this last year, this year's Y7 was a high birth rate year).
I considered Cottesloe and Waddesdon (Waddesdon is incredibly to get into), if DD failed. My absolute favourite was Sir Thomas Fremantle in Winslow.
As it happens she did pass her 11+ so she went to a grammar school, so I agree it may be worth having a few hours with a tutor (we couldn't afford a tutor and then it was lockdown anyway).
Honestly, I'd take Lord Williams over PR, but PR is preferable to a lot of Aylesbury secondaries. Look at Sir Thomas Fremantle too.
The best thing to do is to look around schools, no amount of recommendations can beat the 'feel' when you look around a school and see if it's a good fit for you.