Have you met anyone that you just couldn't get enough of? That if you were chatting you wished you could talk about everything and if you were playing you could just go on and on till passing out?
That's the person you book a longer date with.
One wonderful thing about this world is that there are people who like everything. If one hour is perfect for you, you'll definitely find women who share the preference. Some gentlemen prefer a more "civilian" date like experience knowing that the cat is in the bag for later. Whether it be a three hour date that starts with drinks at the bar or a 5+ hour date that include dinner and/or a show before (or after, or my favorite- in between) playtime.
The funny thing is that the longer the encounter generally the LESS sex happens. It drives me so insane. Like, hello! LOL. The tortures of having a strong libido.

But usually there are full days planned out with a robust itinerary. The best part about longer dates is that you tend to actually do things together besides just playtime. When you are friends as well as lovers this gives shared experiences to bond over and enjoy. Sometimes- just sometimes- it's actually about companionship and having amazing sex sprinkled in is the cherry on top. Plenty of my patrons want to do things or go to places that their wife doesn't want to do. Well, I do!
To actually answer your questions though... The benefit is simply getting to relax more in each other's company and get to know each other better. The more she understands you the better of a date she can tailor to you as the night goes on. It gives her a chance to be all you want from this world. What else goes on? Anything and everything. Many women will be happy to play concierge and plan out a day for you both. We tend to love adventure and exploring, even if it's in our own backyard. I'm passionate about sharing "new york" experiences with people and those are the best things to share on a long date. Something "local" that can't happen elsewhere.
Or, you know, you can always just stay in the whole time .
Kiss me,
Kate