Had an interview with them a while ago but didn't get the job. However, I found them to be very friendly and they gave out a nice smell.
The day was run in a fairly relaxed way. There was a short technical test on the B737 for type rated applicants. Also a verbal reasoning test and a mental agility test which involved interpreting data from tables. The usual psychometric test was included. The interview was fairly standard in front of a panel of three. Questions about behaviour (popular these days) were included but the rest was pretty normal.
The big question was whether you were prepared to move north for the new Jet2 operation.
What I would say is this. Compared to the new breed of low cost carriers this seemed an old fashioned company. More recognisable in culture to those of us who have been around a bit.
Good luck if you get offered the job.