It depends where you buy the Pro-Comps from as to what components you get. I have bought a few pairs from a shop in WV that does their own machine work and installs thier own valvetrain, PBM valves, springs, Viton seals, etc... I've checked the valve job, guides etc and have found them to do be in spec. Now that being said they are far from the best flowing heads available but for the run of the mill combo and budget, the $700 head works well. I have a set of the 210cc versions on a 11.8:1 393, goes 10.10 @ 130mph in a 2550lb car, with some converter issues. I think the car will go 9.80 @ 135mph once the issues are worked out.
You can find the Vic Jrs at times around the $1000 mark, they are a good choice for a 190cc head as well. Now if you price out porting a Pro-Comp to get them to flow decent you can afford a AFR205 that flows better right out of the box.....
My choice would be a AFR205 but it just is not in everyones budget or needs....
