You can chop very heavy with both short (eg HOU Yingchao) and long pips so I don't see any reason why you can't chop heavy with medium pips. I have briefly tried it and found it quite nice for chopping heavy.
Also, 'tricky reversal' is only relevant against inexperienced players up to a certain level. There is the 2 colour rule now.
Yes, Hou Yingchao and Ding Song use(d) short pips. Short pips have some bite to them and some are tacky/grippy. Medium pips scrub the spin off, but can only modestly
add the spin back on because they "give." The fact that there are no world class men using medium pips points to this (although Liang Ge Liang said he once used a "long pips" rubber that today would be classified as a medium type pips). I highly question whether a medium pip can give the same type of rip chop like Feint Long 3 or TSP Curl PR-1 (or 4). you can get a driving type chop but it will not have the same viscious under spin because the pips can not bend. This is ok until you run into a 2200+ looper who finds that your modestly spun chop actually helps him on the table-Oh happy day! The only way to vary your spin is to twiddle which might be effective for a player like Filus. I realize that Ai Fukuhara uses them to defend but I am not sure she faces the fast loops that you find in the men's game.
Agree on the reversal-rarely see this with nationaly ranked players, and I have yet to see it with the advent of 2 color rule.
For offense your only choice of attacking shot is flat hit against any player who has decent attacking strokes. I have tried hitting top spin drives with my backhand to find as I described-a screaming fast loop coming at me or a smash. The plus of medium pips for me is if I can land that flat hit on the table my opponent has problems because it: 1) has a very flat trajectory, 2) is very dead, 3) is traveling at a very good clip ( I smack 'em in hard).
For my game, I need the top spin drive stroke to keep my percentages in the acceptable range. I was so impressed with Miao Miao's game I built a copy of her paddle and play with it-she uses medium pips on the back hand side (and short pips on the forehand). I am a huge proponent of medium pips, but there are certain things that I dont think it does very well.