I have to say that I am a luggage hound. I am always on the look for bags that will fit my particular needs, as well as my frame. I found Tom Bihn bags on the onebag.com website, and have purchased a Tristar, which is nice, but I really needed something smaller for a solo trip to Hawaii for a conference. I would be visiting three islands, with hopes of overnight camping on one of them using my camping hammock, so the bag needed to be big enough to get me through ten days of travel (including hiking and camping) on three islands with just me. I contacted customer service because I had read great things about the Synapse 19. Someone suggested I try a Synapse 25 for 10 days' worth of gear, so I went with that. I have not been sorry.
Typically when our family of 4 travels, we do "carryons only" anyway, so attempting to travel light is nothing new. But this was a real adventure for me in trying to make it 10 days with only my Synapse 25 and an LL Bean nylon tote as my "personal item." Packing the Synapse was easy, once I figured out where I wanted each parcel to go. I tend to use packing cubes so that I can keep track of my clothing more easily (sorry to say they weren't Tom B). I love the organizational possibilities, and the balance of the bag with the water bottle pocket in the middle. It is rather like the wardrobe in the Chronicles of Narnia - much bigger on the inside than it looks on the outside. I got it in the Dyneema blend to shave off a few ounces of weight.
I had a great trip and although I didn't use my camping stuff (mailed it home after my camping opportunities had passed), there was plenty of space for my hammock, rain fly, bug net, ropes and stakes, as well as my clothing, water bottles, toiletries and other small necessary camping items, plus a Bluetooth keyboard and my Kindle Fire in place of a laptop, and all the electronics accessories needed for that and my phone (split between the Synapse and my tote bag). The pack never felt too heavy (even when I had loaded it with 20 pounds of stuff). I am 5' 3" and about #120 and I didn't find it too big for me. It fit beautifully under the seat even on the smallest commercial flights.
Fast forward a few months when I took a short trip for a conference in Atlanta. My packing needs were very different but I took the same two bags and it worked great. Since I was going to be sitting in lecture for 30 hours, I brought along my chain maille jump rings and pliers to "process" the rings for my jewelry business - something I often do when I have to sit and listen for long periods of time. (It helps me to listen better if keep my hands busy.) So I had three 1/2 gallon zipper freezer bags full of aluminum rings packed along with my clothing, and it wasn't as warm in Atlanta in February as it can be, so I had some warmer clothing as well.
So far I've only taken two trips with my Synapse 25 but I look forward to many more. I have friends traveling to Israel in the summer and I've offered to loan the bag to them, and I plan to take it on our family vacation this year. I think I'll have to make more travel opportunities for myself so that I can use the bag more. I highly recommend it, and the Tom Bihn customer service people for their advice. I wish I got a commission for advertising the bag, because I tell so many people about it. :)