My front wheel is motor so I stuck with standard shimano cable v-brake for front.
I had Magura HS11 (rear only) ran for 18 months, I second the above. I found that the lever went spongy quick and I found my self adjusting them weekly, however I gave up and got used to the spongy due to the fact that having them perfectly adjusted was bowing my wheel and causing bearing wear, ie to sharp braking. Fixings wear with constant adjusting and cleaning.
I now use promax rear only, although spongy lever, these aren't as bad. IMO if your want instant stopping power then I feel standard is the best however they squeak a lot with high speed of ebikes. If you want slowing down the hydraulics are fine & don't over adjust. Promax are a slightly more painful to change pads it looks quick release but I couldn't figure it out.
Never bled any brand I will just replace. Magura, if you can get hold of UK CS if it still exists then I found them helpful with spares for free.