I've saw this question asked once before. My perspective remains the same and has served me well. I personally love the hour, I've been know to book 2 hours for duo's but, for first dates, I don't just book an hour with anyone.
My hour is reserved for:
-A well established (G F E) lady or agency with a good website, a good gallery, good reviews and that states GFE. This is because you are pretty much, based on my experience, going to get what you are hoping for both physically and service wise.
Also, if they are a fairly established lyla member that's always a major +, but I need a gallery no matter what or where they advertise.
My half hour is for:
-Backpage unknown roll of the dice. I am very selective in which ads that I'm willing to risk my safety and money on but still the risk is so much higher when browsing on forms like BP.
If you are a little bit unsure its better to book for the hh in my honest opinion.
Now if you get there and you're like...wow....super happy, it's easier to ask if you can increase the session to the hour as that's actually a compliment
But walking in and saying...um...can we just do the half hour instead is more than a bit awkward.
Having said that, if ever you feel you were bait and switched...I feel it's our duty to turn around and leave even if it's awkward. Staying only perpetuates this sleezy behavior, contributes to the dark side of the industry and makes it more difficult for legit ladies because we as customers become jaded and paranoid.
So in short, out side of a busy schedule, risk dictates session time.
High risk, short session
Likely bliss, long session