Truth!
I've done 135MPH on a motorcycle for about 10 seconds. That was enough.
Did ~150 on the track at Charlotte (no speedo, but I got yellow flagged for exceeding the 135 class limit) and again ~150 (240KPH) on the autobahn. Again, enough.
While doing 240KPH on the autobahn, I got passed like I was standing still by a Porsche, who nearly crashed into my buddy driving ahead of me who changed lanes to make a pass and didn't look far enough back to see the Porsche inbound like a jet.
I'd be cool with going faster on the track, but even the autobahn isn't the place for it.