I initially thought I had a reel seat problem but it was my own fault not taking time putting on my reel...it wobbled slightly. What I would recommend is putting tape or tabs on the reel feet because the metal on the reel seat(metal screw) can scratch the reels paint. Mine are already scratched so it doesnt matter anymore.
I use the 7ft mh for almost everything including what you want and I dont find problems with it at all. I even throw finesse jigs on it. Ive never used the medium to fish so I cant compare it, its slight lighter, but the mh is light too. It is stiffer than other MH rods but I actually prefer it to my other m/h rods and I've said its my favorite that I own.
I put my revo back on it, with 50lb braid and have been using a flouro leader recently, I think the sensitivity has stepped up even more now with the leader on the soft plastics. I have the micros, the knot (that I use) passes through but can rub so I usually stop it before the tip. If you are using regular guides or straight line no leader, should have zero issues there.
I think you'd be happy with either the M or MH the mh would give you more options IMO if you decide to go into heavier cover