yea Mr hunter, the way I see it it's a trade-off, short session with a young/hot WL vs long session with MILF, sometimes you get a great MILF with great service (tough to find these days), otherwise you are stuck for the hour.
For the 30 min sessions, I usually take a shower beforehand, so when I get there just 1 min in the shower then out for action, some places the girl shower with you and clean you up etc, keep in mind 30 min session is a double edged sword, some budget/mid-end shops only allow you to cum once, so if you are a "cum in 5 mins" kinda guy then once you cum that's it, you either stay and chat or get a crappy massage, both waste of time, also with some places they cheat on on time, so 30 mins may turn out to be 20 mins + shower...places like Ginza or N5M are much better in this department.
Basically for 30 mins session expect it to be a bit more mechanical and rushed, imo you gotta go in with a loaded gun and ready to shoot, as there will be less build-up to the climax, you go in fuck and cum, that's it and that's all.