My cruising speed is 200-220 in general. It seems to be a good middle ground. Bursts of speed and sustained high speed runs not always possible, but darn fun (and legal!) when traffic conditions are right.
Your eyes get used to fixing as far out as you can see after a while, and watching for telltale signs that occur before someone pulls out without indicating. You start getting an eye for speed differential that when I first moved over was not there. Also, cars always nudge out before changing lanes. I can only guess that this is the head turning to look in the rear view, which moves the shoulders ever so slightly, and it translates to a shift on the grip on the steering wheel. This is generally almost a second before they put on their indicator.
When I top it out, I will let you know. The car just sits in the garage most of the time, so be patient. I bike more than I drive.