They took the first 5 hours of the original game and turned into 40 hours. The Boss fights can't be shortened by much even with a good strategy, you won't be able to deal an immense enough damage to make them short. They'll either be kinda long or really long. They're show pieces with minor cutscenes splice through out. Every boss has weak spots, and ailments that they're susceptible too. A lot of your highest damage output is through the command menu. I just beat a boss that pretty much rarely stayed still, it had a weak spot on each side but it kept turning non stop. Trying to use an ability on it would only connect if you're close to the right side and it was turning towards your attack while it does its wind up animation. I found the best method to every fight is to constantly switch characters.
So far the game is beautiful, the voice acting is really good, and the combat is pretty fun.