It was quite the ride, even though some couples were a lot less fun than the starting ones. I still remember the days where people were dreading the 'Dicklet Namek' saga, especially because that one had a route split. I think the last pretty good pairing(in my opinion) was the Kuudere sensei or the hikki sensei , but I could just misremembering... too lazy to re-read that far back right now.
All in all.. I'd probably just rank the series as a whole at a 6 out of 10. Lots of one-on-one stuff between the leads was nice, ecchi and the bodies looked good, but there was definitely a drop off in how fun the student x sensei pairings were. Hope the author enjoys a nice long rest and takes care of himself; never take your health for granted!