yes really got to go down the lighter wheels route sometime soon, does seem that the 6 inch/190 route seems preferable over the 5.5/180. probably more so as power increases.
Go for it mate, its the single biggest improvement oyu can make to the bike! Mine only ended up costing me 600 quid, as I managed to flog my ally 5 spokes for over 600 on ebay
DJT - found the same thing on Rennsports regardless of tyre pressures. Switched to 207GP and latterly pulled the head angle back. Steers far quicker but nervous on fast sweepers, with a gentle wag on the bars when on the gas at fairly big speeds (run an Ohlins damper set on the soft side).