I ran Pilot Sport A/S 2s, Turanza Serenities, and Primacy MXM4s back-to-back-to-back on the same car. I'm back to MXM4s on my current DD.
As said, the Pilot Sport is quite a different tire than either the Turanza or the MXM4. It killed the other two in dry grip, was not too bad wet, and and overall was the best handling set of tires I had on that particular car(Lincoln LS). They also gave the harshest ride, the most road noise, and lasted the least amount of time.
Honestly, blindfolded I doubt I could tell the difference between the Turanza and the MXM4. Both are comfortable and quiet touring tires, and as I recall are a fair bit heavier than PS(in the 235/50R17 size I used, I seem to have a number of 19lbs in my head for the Pilot and around 25lbs for the other two). Dry grip is excellent with both-it's not as good as the Pilot but for any sane street driving you probably have bigger worries if the dry grip of any is a problem. Still, I'd give a SLIGHT edge to the MXM4s over the Turanza when dry, but I'd say it shifts VERY slightly toward the Bridgestone when wet. I didn't see any appreciable difference in snow grip between the two-both are about as good as you could ask of an all season, and better than the Pilot.
My next set of tires on my daily will be either Turanzas or MXM4s, but in my experience they're similar enough that any specials or promotions running at the time I bought them would probably make decision for me.