[Quickurt]

As you can see by my siggy line, I bought the Sumis.
Only about 1k miles, so far, but am very happy with them. They are more sticky and more quiet than the PS2s they replaced, but the PS2s were GONE, so take the comment with a major grain of salt. They're better in the rain, but the PS2s were almost slicks!
I did extensive research on them and found two tests that included PS2s to Bridgestone RE050s in one and RE050s to HTR ZIII. The Bridgy number on the tests was almost identical (7.2 in one 7.35 in other). The PS2 number to the HTR number was about 5% different, with the PS2 higher (7.92 - 8.15 or there abouts).
The HTR's points loss was wet traction. Dry traction numbers were identical to PS2.
Now, considering I could buy a complete set of Sumis and two new pairs of rears for less than the PS2s, I sure don't see it as being a "cheap ass" as someone said above.
I also bought the OZ wheels at the same time, but I think the Sumis were about $725 mounted and balanced, plus freight.