As others have said, I think it's great for someone in Barry's position to come on here and engage/seek feedback in this way. To add my 0.02, I use Peckham Rye station regularly. There have been a lot of improvements recently in terms of smartening up the station (painting, redoing the stairs, fixing the broken announcement speakers).
I also find the ticket office opening hours a bit random - one thing that happens regularly and drives me nuts is in the early rush house (8am ish) when both windows are open in the ticket office with queues at both, but then one window is closed by a member of staff for no apparent reason and despite the queues. Presumably this is for staff breaks
but the timing seems insane to me. To balance this out, I should say that I think the attitude of the staff in the ticket office at Peckham Rye is great - I always get a cheerful and friendly "good morning madam", they look you in the eye, listen to what you want and you never see them on the phone or chatting amongst themselves whilst serving customers (a sharp contrast with Blackfriars which is the other ticket office I use).
One thing I would like to know is how/where the ticket barriers are going to be installed in the station - the staircase up to the platforms is pretty steep and gets jammed up easily, so I'm hoping it's going to be well after the staircase, as you go up to the actual platforms. I was coming home a couple of weeks ago and they were doing a ticket check at the top of the main stairs (having closed off one side). The press of people was so much that I basically got pushed down the first few stairs. No harm done but I wouldn't fancy that every day.