5.75" wheel
Different strokes.......
I bought a set of PVM's a few years ago for my 996sps and the rear is a 5.75" I could have got the 6.0" same price, yet using a 180 w/ a 5.75" works quite well and allows me to use all the tire, no slippy, great hook up, and I probably have about the same HP as your 998, 135RWHP.
A few other 748-998 boys up here in northern California, still use the 5.75" rim for their older style Ducs @ the track, yet if I was stuck at long/high speed tracks I might buy one, but for Sears Point/Thunder hill stuff I do, I have great "hook-up". And when riding on the street it costs a less for rubber......
Track-days/fast street riding and full racing are two different games.......
That's my 2 cents..
Cheers,
Mark