I largely avoided answering this question for a bit until I got my hands on the PST and SS and looked at them side by side.
At the moment, I have a 3-15x42 SS and 4.5-14x44 Vortex HS-T (same basic optical system, I think as the PST 4-16x50 albeit with a different objective lens) and the SS is a little better.
Between the SS 3-15x42 and the PST 4-16x50, it kinda comes down to what is more important to you.
I'll make some extrapolation here, but please keep in mind that I have not had the 4-16x50 side by side with the SS 3-15x42, so this an educated guess.
Ultimately PST is a more full-featured scope, so if you want a zero stop of sort and reticle illumination, PST is your best bet.
Overall optical quality: SS is a little better
Overall mechanical quality: I have confidence in both scopes
Turrets: Probably a wash (comes down to personal preference; I like both designs)
Adjustment range: SS has more adjustment
Zero stop: PST has it vis a stack of inserts. Not perfect, but it works OK.
Field of View: PST FOV is wider
Eye relief flexibility: up to 10x, I like SS a little more. Above 10x, PST has a slight edge to its large objective lens.
Low light performance: both are quite good. SS has an edge at lower magnifications until the PST's larger objective lens starts to play a role.
I hope this helps.