What UD say:
Upgraded lightweight hook and loop sternum adjustabilityTwo rear zippered stash pockets for optimal safety and organization
Small weather resistant pocket on Shoulder strap for chapstick, tablets, and small essentials
Comfort Cinch™ 2.0 - more minimal, lightweight, and adjustable
Shoulder strap shaping to promote weight distribution and comfortable fit
Lightweight 4-way stretch with rip stop pattern for added durability
Front stretch mesh pockets are phone compatible
Corded elastic for external gear stash and overall compression
What we say: This one is down to you guys, you asked, we delivered! I have tried the packs myself and they're excellent, particularly the comfort-cinch which is really easy to use on the hoof. This is the 2020 updated version which replaces the Ultra Vest 4.