Low balls's issue + on-the-run acceleration + DTL shots
1) Low ball issues
Can you watch this point from Wawrinka: youtu.be/tV27ZFjYksk?t=296
In TE4, characters cannot go down on their knee to hit a powerful shot like real life players do.
Players' models seem like dislocated puppets when they try to hit a low ball like that. It makes the game weird, makes you feel powerless, your shot will fly high without speed with a weird anim going backward, as if the guy lost its balance and power.
I wonder why this does happen as this is not a difficult position to cope with in tennis. It was also possible in TE3. That's one of the biggest issue of the game in my opinion.
2) DTL shots lack precision and power: it's almost impossible to paint a line DTL with speed on the run.
It's a high risk shot in real life but here, in the rare instances a DTL manages to successfully cross the net, it will often land 3 meters inside the court or out. Never near/on the line whatever you stats are in precision, consistency or power.
I think 70% of rallies are crossed in real life but perhaps 95% in TE4 because of that issue: it's a high risk, low reward shot, it's not fun, not powerful, not precise. So nobody dares hit DTL.
It restrains options and creativity: you go less to the net for instance as your DTL approach generally sux. Thus we experience a low variety in rallies... or AI coming to the net in bad conditions as I mentioned in other threads.
3) Absence of the on-the-run 105 mph acceleration when players go all-in in a rally: we can see Alcaraz Thiem and a lot of players doing it. It's a shot they make when they bet everything on it. I think it could become an Ultra acceleration hidden button that one can only hit with a tap, or a double tap on accel button. Would not work when you're static.
4) Bonus: players stats normalization + "all-court" style players rushing the net after a bad DTL (which is potentially linked to my point n2: all court AI players think they hit a good DTL approach shot, so they rush the net... but it's not the case, you can very easily send back their approach shots, as they're slow and 3meters inside the court.