Western U. S.: whatever I think I can get away with. IOW, if I can see for multiple miles with few cross roads and driveways, then it's whatever I feel comfortable with. Though with western speed limits of 70mph and up, one can comfortably get away with 85mph, which is fast enough for me. Much beyond that, on the bike or in the car, and it gets tiring and the difference in fuel efficiency is huge (28mpg or less at "spirited" speeds on a bike that normally gets 42-45mpg). And the last thing one needs in a vehicle with a 5 gallon tank, and an area with few gas stations, is poor fuel efficiency. With increased fuel stops, I'm not convinced that one saves a minute of time after a point.
In this instance, think of the U. S. more like the EU. We have Montana and Nevada, they have Germany. We have Ohio, they have (for lack of a better example) the U. K. with speed cameras everywhere (yeah, yeah, Brexit; bear with me for this example).
Here not only do I rarely see cops, I've read in the local papers that cops can't pull people over for speeding if EVERYONE is speeding. You have to be speeding far above average. So everyone is actually incentivized to speed together.
When I first got here I saw comically low speed limit signs - as low as 55mph on freeways! And averages of 65! That's INSANELY slow for how big these freeways are! But apparently it doesn't matter in California, here everyone just speeds and is protected as a group.
I don't doubt that I'll pay my dues eventually. You don't get away with 95mph on a sportbike forever. We make targets of ourselves. That's fine, in Houston I got ticketed ~200USD every three years or so, that's a fair price to get to go above the speed limit for me.