I really don't fit in to any of these categories.
I make the fastest progress I can without exerting too much effort, and whilst assessing risk of getting caught if I'm speeding.
For example - The M3 is free from fixed cameras, rarely see traffic cars or mobile cameras and is usually relatively quiet. 80-90MPH is easily achievable in a relaxed fashion.
The M25, however, has all these Gantries and loads of traffic, so here I'll sit at around 70MPH.
In both instances, I use lanes properly.
Back home, off of the motorways, I stick to speed limits pretty much religiously, with the exception of national, where I'll usually drive to the conditions first and my mood second (No number, no limit, amiright?)