I've owned one and it's like a few other Petri's I've owned. The ergonomics, looks, and design are very pleasing, but the build quality is not too durable. That said, it can make a very nice collectible if you get one that is working or you want to have it repaired. I believe they had a model with a faster lens too - quite sought after by collectors and such.
Petri had a certain sense of design acumen; they made nice use of color engraving and fine aspects of metal work to make pleasing SLR's, lenses, rangefinders, etc. Petris feel nice to use and carry around and, like I said, they look good (and perform optically pretty well). Their contemporaries a the time such as Nikon and Pentax seemed to focus more on engineering high-reliability and have endured today because of it.