All three work well....Like CGretired I have all 3 as well...the only real draw back to the 1 horn with a connecting rod is the connecting rod can loosen and cause slop...an advantage 2 the other 2 methods is if you break a control horn you might have a chance to save the plane with the other elevator half, and of course the same with 2 servos and 2 channels if a servo goes bad....I've only had 1 servo fail in flight..so the bottom line is they all work well...
Good luck