“albert front tyre and I can feel the drag it makes”
The aerodynamic difference over any other MTB tyre is going to be neglible no? Itll be the the tall square block (unramped) tread that’ll be draggy?
“runing 2.3s at the min but think there a bit slow”
What tyre and on what rim?
eg a 2.3″ Conti Vertical on a mavic XC717 is going to be a fair bit smaller than a 2.3″ Specialized Eskar (or 2.3″ Conti Baron) on a ZTR Flow rim
“am i missing something here”
While a narrower, higher pressure tyre will roll better on a perfectly flat surface, eg (theoretical) road riding, when things get rough/uneven, a wider, softer tyre requires less energy to deform it to the terrain, so is supposed to roll more easily, or so the theory goes