Prothane and Polyurethane are basically the same.....although different manufactures used different grades and compounds to effect the properties like hardness. Ploy does very well with compression loads but is prone to squeaking on rotation. So where possible use poly bushings that have a grease fitting. I have always had good luck with Energy Suspension products.
All that being said, when I replaced all the bushings on my 79, I decided to use rubber ones. Mostly because I am not taking the vehicle to the track (its a daily driver), the original rubber bushings are a good design (I used MOOG), and I didn't want to deal with the "squeaking" issues poly bushing are prone too. I did however use Energy Suspension ploy sway bar bushings, end links, and leaf spring pads. I also plan on using poly body bushings when I replace them.
