I was a member of the Fife TB9 group until last year when myself and one of the other members decided to purchase a C182. Only once could I recall having to put my hand in my pocket to fund anything - that was c £100 for a new altimeter. All maintenance including unplanned work was covered by the monthly and hourly rates. Also several shares have exchanged hands since the group was formed so there should be no worries of being stuck if you decide its time to move on.
This was my first experience of group aircraft it was all positive. The best thing about it is the freedom to book the plane for as long as I like (within reason) and go off for a day or weekend. No need to comply with flying school booking slots and minimum hours. I could also turn up and fly in the evenings until 9pm when the flying school have all shut up shop and gone home.
It also generated quite a few lasting friendships and the opportunity to share the flying experiences and costs.
The TB9 is an excellent first aircraft. Its easy to fly and looks great on the apron. Cant imagine why anyone would want to continue flying 152's and PA38's after the little brown book drops through the letter box.