Energy management is one of the big struggles pilots have with the 800. I've jumpseated on the 737 a number of times, and it's been something that the captain comments on every time in the approach briefing. I've also seen the speed brakes used extensively in the descent. If they're planning on a short approach, then they'll sometimes drop the gear early to help in getting slowed up.
High energy approaches are also something I keep in mind as a controller, and we've been told to be keenly aware of the workload that it can put on pilots. If I have a sequence where I can put a 737 on a short approach, I'll look at the type. If it's a -400 or -700, then I can usually get them in pretty tight without any problems. If it's a -800 or -900, then I'll think twice before trying to set them up for a tight approach.
If you want to get a taste of how energy management works in the real world, next time you fly an approach hold 210 kts to a 15 mile final, and then 170 to the FAF. This is typically how we set aircraft up on the finals here at IAH. It can be challenging, but I find it to be a satisfying way to fly approaches.