I've always found the staff at Pentimento to be helpful and accommodating. When I've asked prices on items where it didn't appear clear they've acted promptly and professionally. Books I've bought (which are always for presents) have always been wrapped beautifully and with a smile. Maybe the difference is because I'm there to buy things :)
I jumped on here to find their phone number and saw all these neg reviews and was kind of surprised. Anyway, I called up as I'd seen a book on Stanley Kubrick there (and other great point about their store - where else would you find a book 4 inches thick on Stanley Kubrick's unproduced Napoleon project and screenplay?) the lady I talked to was friendly and helpful, found the book (as I was asking for the price) and has put it aside for me and I'm heading up today to grab it.
For me for one I like that they don't hound you while you're browsing and offer to 'help' etc. I want to shop and generally be left alone until I need their help. As to the writing down names of books - what's so hard to understand about a retail store having a policy in this day and age to protect themselves?
Anyway, I just wanted to offer a contrary opinion to the negative ones.