The way I see it, I'm not really competing with anyone except myself. What matters to me is how well I communicate with my car, and how hard I can push the limit. This would be true for 7s or 48s or whatevers. Its not 'can I go faster with 48s?', it's 'what's the fastest I can go?'.
That being said, I'm investing my money into things that improve me, and my interface to the car - better seating, better pedal placement, etc. On the second tier, I'd like to invest in tunability - adjustable sway bar, adjustable suspension.
From my tires, I want predictability more than I need performance.
'05 SB Elise, TP, ST2, dual HID, driving lights, 4tress, schroth 4pt asm, TP rail, SYS, CRD, microMirror, HNTpad, V1
'13 Abarth, Nero/Bianco
'07 MINI Cooper S, lux, nav, MY + steeeripes!
'12 CLS550 land-yatch