Recently received my Synapse 25 and have mixed feelings. As background, I have had my ID for awhile and love it, but recently wanted to supplement it with a backpack. In short, it is fine but there are three things that make it not the perfect bag I expected. (nb There is not anything wrong with the bag per se nor was it presented unfairly, but rather I realized there were a few things I would have liked better.)
First, it would be great if there was a section in the Synapse like the ID for pens, business cards, etc. beyond the small sections in the side pockets. I loved the side pockets in my ID for glasses, phone, etc., but with the Synapse I am forced to make a choice. It seems like a small section could be placed in the main compartment, bottom zippered area, or adding a separate zippered area added with the "organizer" included in the ID.
Second, I understand the benefit of having the water bottle holder in the middle, however from a practical standpoint it just does not work for me. I often grab smaller disposable bottles of water at airports and cannot take the chance of bottle sweating damaging my other items in the other pockets because of the sewing-related holes in there. In addition, it is more difficult to grab the bottle while walking, etc. with the current location.
Finally, in the main compartment it would have been great to have a separate laptop area. I know I can add the various components, but after trying them they just don't do it for me. Having an area built in where I can just slide my laptop and grab it when I get to work would be great. Does not need to offer perfect protection, but a separate compartment would be great.
Again, my Synapse 25 is a fine bag, and much roomier than I expected, and maybe my issues with it are unique. But, as a professional using the bag for business I know these few changes would make it perfect for me and I expect others as well.