The Datsusara BPP is a great bag, larger than the core, and has an extra Velcro space in the front of the bag which for myself is much needed. I had the battle pack core for 3 years and then unfortunately I washed it and it ripped. So I needed to get a new backpack, and decided to try out the BPP. It has been a few weeks and I like the extra space it has in the bag. My only concern with the bag is that since it is much larger, more things will be put into it, and with the extra weight I'm not too sure how well the shoulder straps will hold or for how long. Like I said I have had the backpack for two weeks, and I had the core for 3 years, so I have faith it should live up to its predecessor. Great backpack so far!