Well, from my experience, PL Squats are a LOWER BODY mass builder while BB Squats are more QUAD specific. PL squats tend to tax the posterior chain more- glutes, hams, lower back.
Personally, my best results are when I powerlift squat and then do conventional deadlifts. The conventional deadlifts seem to give me all the quad work I need and, if I need more I usually hit the leg press. Most athletes and BB's I see have enough quad development, but are sorely lacking in the posterior chain.
Back to deadlifts, personally I see the best results with conventional. Sumo tends to work better for shorter limbed lifters and seems (on me at least) to hit the posterior chain a little harder than the back. RDL's are almost completely a hamstring exercise, but work the lower back as well.
Try them all. See how they feel, what you like, etc. Variety is great for building up legs and back.