it's cute - but the shift pattern is wrong for a 915 :-) ...
i still like my
plain ol' MoMo aluminum ball - have a look at Porsche factory race cars and think how many shifts those cars get in 24 hours at Le Mans or Daytona.
i bought mine when i was doing combat-zone commutes on the 405 between the San Fernando Valley and Manhattan Beach -- 10,000 1-2-1-2-1-2-1-2-1 shifts a day...
it does get hot on hot days, but you shouldn't be resting your hand on the knob anyway - wears the shift forks. but on the track, you should be wearing Nomex gloves anyway, and in the winter, i'm usually wearing some kind of glove too.
Titanium is actually more dense that aluminum, but if you want to make sure you'll have -something- that will survive that nasty FI fire, there are
Titanium Shift Knobs .