I know with Shimano that but master and slave cylinder/piston sizes are the same for both road and MTB twin pot brakes so they are as powerful as each other. The real difference IME is hand position on the levers, your hands can pull MTB levers more easily.
I'll learn to do it myself if it's going to be a semi- regular issue..
A: learn to bleed them yourself anyway
B: you shouldn't have to do it very often if the bike is kept upright. Laying bikes down or turning them upside down is the main non-failure cause of air bubbles in the hoses
I had this overheating brakes. Do the bleed, you should change fluid at least every year, and you may have air, too.
Road hydros do indeed feel less powerful than 20 quid shimano MTB brakes, but the right pads and a good bleeding and bed-in make a lot of difference.
I know with Shimano that but master and slave cylinder/piston sizes are the same for both road and MTB twin pot brakes so they are as powerful as each other. The real difference IME is hand position on the levers, your hands can pull MTB levers more easily.
Sounds like they need a bleed.