Time to report back on them. So far I have around 200 miles on them, so they might get a bit better but otherwise good to go.
Ride quality - Difficult to tell on a modified Impreza, perhaps a touch better, but definitely not any worse than before. The sidewalls might be a touch less stiff.
Noise - This is where a significant difference comes about, these tires are much quieter than the star specs! They still make noise of course but they don't howl like before, more of just typical tire rolling noises. On some rather new and good pavement the noise level dropped significantly, and I was rather impressed by that! The Impreza is not known for quietness so it's a nice benefit!
Weight - Each tire is a good 4lbs off of a comparable star spec, and I can tell. Mostly in low speed maneuvers the wheel is not as difficult to turn. However this could also be because I feel this tire has a smaller contact patch so it's not gripping as much. Eitherway I do feel a slight difference having 16lbs of rotating mass out of the car, perhaps I'll see a slight mpg improvement.
Braking - I feel I might have to give the Star specs the edge here. Very rarely could I ever 'lock up' or induce ABS with those tires, but I've already been able to get some squeaks out of these PSS's under hard braking. It's not hugely different, but I do think the SS's were better in my car but only slightly. Tests will probably prove me differently.
Handling - This is a real difficult one to give any edge to. I've managed to get some squeaks from the PSS's, but not slide. In my latest test I did feel them sort of break free but then it almost feels like they got a second wind and caught again. I only did a quick mountain road test for this, so when I go on a more extensive one I will know better. They both feel really nice, grip really nicely, and seem to break away cleanly. The PSS's might be louder though, the SS's rarely made noise for me even when sliding.
I have not had a chance to test them in the rain, so that's yet to be determined. The SS's really impressed me there so I'm hoping for good things. Overall these PSS's seem like a rather good tire. They grip well, are quiet, and have a nice treadwear rating. I can't really speak on the feel of them to well, WRX's aren't known for steering feel, but the car feels planted and what I can feel through the wheel is fairly communicative. They also feel really well made.
If your trying to decide between the two tires, it becomes really difficult. The SS's are a decent bit cheaper, but don't last as long, however I feel they perform nearly/as well in most cases to these PSS's. We shall have to wait on the Tirerack's official testing figures to really find out.
