I've been using the 3A-5TS from last year as a work bag almost everyday since I got it from it's drop. Thought it would be the bag I'd use for the next 5 or so years, but then along came the 3A-5... Here's a little writeup of a comparison between the two.
For a little context, I commute to work by bike everyday and have to carry a 15 inch laptop, a change of clothes, and an extra pair of shoes. The size of the 5TS and 5 perfectly fit my needs, but the differences on the 5 were surprisingly helpful. The obvious differences are the roll top lid and the two giant fixed pockets in the front. My biggest gripe with the 5TS was that anytime I wanted to grab something from the main body, I'd have to pop open 3 buckles and refasten them closed all over again. The roll top feature solves this nicely by reducing the buckles I need to fiddle around with to 1, and also stowing away the excess material of the flap. Much easier to grab something from the bag with the top rolled in when the bag is still strapped tight to yourself.
The two exterior pockets are a nice addition to the bag. I had the first generation xpac 5TS before getting last year's, and a feature I missed a lot were the two built in zipper compartments on each side of the bag. With the newer 5TS, I tried to recreate these by sticking two MZ1's vertically on each side. The exterior 3A-5 pockets hold much more than the MZ1's ever could, making the MZ1's no longer necessary. The mezzanine pockets behind them are really useful as well and serve as a nice little spot to store items you'd like to grab quickly without having to fuss with any buckles or zippers.
Despite the lack of TS, the attachment loops on the 5 work well if you still want to expand your storage. Though the website only demonstrated you could attach a MK1 and MK3, I was able to attach my MZ1's without any issues. While I opted not to use the MZ1's anymore, I've attached a DSPTCH glasses case to 1 loop, a key charm to another, and a grimloc carabiner to another to hold my keys.
A surprising change was the inclusion of two smaller inner zipper pockets as opposed to the single pocket of the five. Though a seemingly minor change, it helps partition my smaller items nicely. Although the single pocket from the 5TS is larger than one from the 5, the combined volume of the two smaller pockets is greater. Here's to hoping including two of these pockets becomes a standard and not just unique to the 5.
There are some subtle differences you might miss that aren't obvious in the product shots. The lid on the 5 is reinforced with 3 sections that helps act as a guide to properly fold it in. It also helps give it a nice solid shape and structure, making the 5TS lid feel flimsy in comparison. Another small difference is the left and right buckles on the 5 can't slide up quite as high as on the 5TS due to the stitching on the thumb-break closures for the exterior pockets. This slightly restricts the expansion of the 5 vs the 5TS. I'd often pack my 5TS to the max fully expanded for weekend to week long trips. Though the difference is small, I'm a little worried for when I'll have to pack similarly with the 5.
Despite the suggestively simpler name, the 3A-5 is in many ways a worthy upgrade to the tried and true 5TS. The 5 solved most of my gripes with the 5TS and will probably be the bag I'll use for years to come, unless Acronym and Bagjack manage to find another surprising way to improve the bag again (which I'm sure they will). Hope you all enjoyed my sincere writeup.