I have ridden with the latest EVOC Hip Pack Pro, the Dakine Hot Laps 2L and the Osprey Savu and they all have features I like, and some that I don't.
The Backcountry Mid Mountain 2L pack is by far my favorite pack. It is a little heavier, but the materials, zippers, and stitching all tell me that this will withstand some serious abuse. The main compartment is nicely laid out and easy to rummage through on the side of a trail.
The outer storage straps are perfectly designed for stashing a rain jacket or a set of knee pads.
I prefer a key clip, but there is a zippered mesh internal pocket that will store your keys quite nicely and stay out of the way. The elastic loops on the inside are great for 16g and 20g Co2 cartridges, I also had some spare quick links for my chain, a larger multi tool (CrankBrothers M17), tire lever, a Lezyne tire plug kit, plenty of nutrition and room to spare. I would go so far as to say that with the way this pack is laid out, it is simply the best use of space I have seen. The pack is narrow, so it is small and easy to forget you are wearing it. The bottle retention can be adjusted with a nylon strap, but I ran mine loose for 20+ miles of resort riding on rowdy single track and Jump trails and never had a bottle try to get out. I was surprised how quickly I forgot I was wearing it. With any of my other packs, I notice them bouncing a little but this stays in place really well, leaving me to focus on the trails. The belt system is tight, meaning that it is not super easy to tighten and loosen the belt strap, at first it was a little off-putting that it wasn't as easy as my Osprey pack to loosen the belt and slide the pack around for access, however, my Osprey pack has been bumped loose a time or two and has even loosened up on me while descending. This pack doesn't budge, so what I was originally put off by I am now beyond stoked on, because I no longer have to re-tighten my pack constantly throughout my rides.
Excellent use of space
Stays put, doesn't loosen up unintentionally
Very high-quality materials and construction, you just know when you pick it up. Zippers, buckles, stitching.
I like the zippered key pocket but I would really like a key clip
Quality materials come with a slight weight penalty, but I'll take the penalty for a quality pack that will last for years
Only one belt pocket and it isn't big enough for an iPhone X but will fit the smaller phones no problem (I usually keep my phone in my shorts pocket anyway)
Bottom line, this pack is fantastic and I will recommend it over any other pack in this category