Hydro discs are lush.
The levers are so smooth and light, 1 finger operation is easy.
The calipers can be a ball ache, sticking pistons, unequal piston push and off centre pad wear.
Changing pads isn't an especially easy trail side job, especially with those calipers that have retaining clips, or like Hope M4s, clips and pins and rods and gubbins.
Removing and fitting wheels can be a pain too, some pad retaining springs tend to push the pads into a V shape and make it a struggle to get the disc inbetween.
Front wheel off, bike chucked in car does equal pads closed and pistons needing to be pushed back in by hand, must remeber to use a packer.
Cable discs.
Same roughness associated with all brake cable levers.
Harder to pull than hydros.
Pad wear uneven on some calipers and they don't auto centre.
Easily changed and tweaked on the trail.
Problems I've had:
Brake pad very ever so slightly off edge of disc, pad wore the tiniest bit unevenly, piston came out at a slight angle and wouldn't return. Pedalling got harder, the opposite piston came out to compensate and then it wouldn't return, locked brake on F wheel.
Had to drain the fluid to get the pistons back in, no front brake for rest of ride.
Contaminated pads. I don't know what I rode through but the pads gots oily. Pull as hard as I could, cable discs, no stopping whatsoever and no way of cleaning them while out.