Perf
Performance
90 minutes still seems the sweetspot. Even BACK in the day when 60 would suffice, why? Outside of the Oz_Minute-man environment, punts divided into ST and LT, where ST differentiated by SOG + TOD. LT... well, hell, it's LT.
In MP's, the difference between 60 and 90 minute pricing is about the same as Oz_land's RnT difference between 45 and 60 minute pricing. So unless you have a plane to catch, pretty much a no-brainer.
In Oz_land, 90 minutes does work. A few shops advertise its availability. Others, book 2 45 minutes sessions, back-to-back. The provider should understand; still, don't be shy about clarifying your intentions.