Played through E4 last night and really, really enjoyed it.
The animations keep getting better, as does the writing, and the humor remains top-notch. Yes, the six new animated scenes in the Wank Bank are with the same characters that (with one exception) previously had animated scenes, but that fits with everyone's character at this point in the story. And there is progress towards building the romances/relationships with some of the other LIs; some of those scenes (particularly one with Naomi) I personally found hotter than the animated scenes. I think my only complaint would be that in my one play-through there didn't seem to be any further development with Dr. Riley after starting to get to know her better in E3.
This chapter also does focus on the main story quite a bit with the introduction of the rugby team and as the MC tries to figure out their involvement (if any) in the events leading up to E1. Apart from that mystery, the episode starts to reveal the tensions between the rugby team and the feminist society, with members of the cheerleader society caught in the middle but starting to pick sides. There are some powerful threads here to pick up in later episodes regarding regulation, freedom, control, safety, etc. that in a way echo the recent AVN censorship efforts (even though I'm 99% positive that the writing for E4 was done way before that started).
It's a tricky balancing act for the dev at this point in the story, as there are people who played some or all of E1-E3 and went "there's no story" or "it's just a fuckfest" and now there are also people who want to to cut to the chase and get with the slower-burn LIs. I get it (we waited almost 9 months for E4) but I am happy how this one landed.
P.S. For me, there was a really, really difficult choice to make with Tasha and Ashley near the end of the episode. Very interested to see how it plays out in E5 and beyond!