djnotts wrote:And while I'm here...."common novice mistake of cycling with knobbly tyres on road, its like cycling through thick soup,"
Clearly I'm a novice, but IMO it depends on what tyres and how hard you pump 'em up.
I accept that some knobblies might be a bit slower than road tyres, but some run really quite well when pumped up on-road, and will give you performance off-road that is impossible with road tyres. I had some tyres that sounded like an air raid siren. All that noise is your energy. My current knobblies do not do that.
It really depends on what your proposed usage will be. When I returned to cycling after a break, I bought an MTB first, so that when I'm out, I can go off-road wherever I see a route that I like. You might be closing off that ability if you go to a road bike. Horses for courses and all that (is there a translation in cycling terms?)