Hi Bryne11,
I did mine for an airline tagged fATPL scheme 3 and a bit years ago and I don't think too much has changed.
You arrive (10 mins early, whatever you do don't be late) and are shown into the reception hall at Dibden Manor. When the time comes you all go into a big boardroom with a long table and sit down to be talked through a presentation about your particular course. You have the opportunity to ask questions at this point and from my experience all were answered honestly.
There were 12 people at my selection day so they split us into two groups for the morning session, half went to do PILAPT first and the other half went to do the group exercise first. From memory the joystick was fine, not overly sensitive. There is free fresh coffee in the main room, my tip? Don't overdo this, I needed the loo within the first two minutes of the test which was quite uncomfortable!
After the morning session you have lunch, cadets stay at the manor for AQC so grab some for a chat, they'll be happy to give you a talk about the rest of the course.
At our day 6 didn't cut the mustard in the group/PILAPT tests so went home before the interview, I believe now ALL get the interview so when you get feedback you can get some used l interview feedback. Interview took about an hour then went home about 6pm (I was last in) so whole day took about 9 hours. Enjoy the manor grounds, beautiful in summer!
Cheers!