Old School RuneScape: Interaction between pickaxe speed bonus and capped XP rates?

Solution 1:

Yes mining would be slower with a rune pick opposed to dragon.

Every pickaxe level comes with a 15% efficiency increase. So by using a rune pickaxe you will be mining at a constant rate 15% lower than if you were to mine with a dragon pickaxe. This would effect your experience rate drastically over a long period of time.