I did all my training in a Piper Warrior (160HP) and like the airplane a lot. Roomy, stable, easy-to-fly. If I could afford one for myself....
As far as partnerships go - I chose the single-owner route. I had an opportunity to buy a 1/3-share in a Cessna 172 for less than my 150. I bought the 150 instead. Basically, it boiled down to convenience - I wanted to own instead of rent so I could pick and choose my schedule, and I wanted sole-ownership because I perceived a partnership being a lesser form of rental hassle.
In retrospect, I would've down well with the Cessna 172. The other two partners fly it a total of 20 hours between them for the entire year. Essentially, I would've had my own plane for 1/3 the price.
However, I don't have any regrets about buying the 150. It's been a lot of fun and well worth it. One of the advantages of sole-ownership is the ability to leave the plane wherever you'd like. I've exercised this option a couple of times when the weather just wasn't too my liking. Not having the pressure of partners or renters removes some (but not all!) of the get-home-itis.
So, my advice would be to look at the logs for that Piper and see how much it flew in the past year or two. You might find it flies a lot, leaving little time for yourself. Or you might find the other partners simply like having options and rarely exercise them.
