No equity shares are fantastic and are a great insight into running a group aeroplane!
I was lucky enough to be asked whether I wished to join a no-equity share when the flying club closed its doors back in 2000. I jumped at the chance. Low monthly standing order (£55 if I remember correctly) and £32 per hour wet for a lovely Beagle Pup based at Cardiff. That was when fuel was cheap(er) and so the fees steadily rose and I believe they are now around £65 per month standing order and £55 per hour wet due to fuel going up etc.
I'm no longer a member of that non-equity group but I made some great friends (namely the owner) and we had a fantastic time. It was just like having your own aeroplane and availability was no problem at all. If, on the rare occassion two of the six strong group wanted the plane at the same time then we just buddied up.
I've now moved to Scotland and have a 1/8 share in a lovely TB9 which is currently in the shed for its annual.
A PA28 is probably on par with the TB9 so I'll just detail ours. I paid £4,375 for my 1/8 share (x8 £35,000) and pay £90 per month standing order which covers insurance, hangarage and home landings, GPS yearly update, annual and other bits and bods. We then pay £66 per hour wet which could go down slightly as the fuel has decreased in price (shock horror) but we've decided to keep the hourly rate the same to build up a bit more to the contingency fund.
There isn't any availability problems and everyone in the group are very friendly.
Having been a member of a non-equity group in the past really opened my eyes to ownership before I actually bought into a group myself. Being used to maintenance schedules, bookings, syndicate agreements, insurance etc are great in deciding whether to buy into a group in the future.
Non-equity groups also give you a great insight into how a group runs and whether it is for you or not.
I'd say go for it, no matter which form (equity or non-equity).