Besides pure speed, another consideration is fuel range. Fuel stops take a lot of time and rarely do the stops fall on the shortest lay line. So there is time wasted for diversion, descent, traffic pattern, landing roll, taxi, fueling process, restart, run up, taxi out, takeoff, climb, etc. It adds up big time. It usually costs me me 30 to 60 minutes at a minimum, and the bigger the airport the worse it is.
If I'm going somewhere, it is always faster to throw in the pee bottle, pull back the throttle, and keep her in the air. Admittedly, my preferred legs are 3 hours or less, but 5 or 6 hour legs are doable if prepared for them. If that eliminates 1 or 2 fuel stops, I'm way ahead time wise. A personal minimum reserve is 10 gallons, or about 1-hour in cruise so I'm good for 6-hours at 117 kts at altitude (above 7,000 feet), or a 700 nm non-stop range.
That can be pushed close to 1,000 nm going above 12k with O2 and tailwinds. on the other hand with strong headwinds, I'm lower and will push the fuel burn up to 12 to 13 gph to maintain ground speed but that is still 4.5 to 5 hours of air time, or just under a 600 nm range.
I'm sure glad to be back on the ground and done flying after those long legs, however. I non-stop Elko to Tucson and the reverse fairly often. Those trips range from 4.5 to 4.5 hours depending on winds. I considered getting a small go-fast to do the same thing then realized with a fuel stop, I wouldn't be saving any time, but it would burn less fuel, but I wouldn't be able to carry as much stuff. Trade offs abound!