If I were to order a backpack, it'd be a Synapse. I really dig the design on them. I prefer messenger bags for my day-to-day, though. I'm saving up for a Tom Bihn Medium Cafe messenger.
I completely agree with the MCB. In fact, in the future, I'd like to get a MCB to complement the S25. It's the perfect "quick trip to the store or park with the kids" bag.
I love the S25. I had the 19 in black/wasabi and it was the gateway to the rest of TB. Where the 25 shines over the 19 is its versatility. It's extra needed space is good for longer travels but also wears and looks good with very little in it. I have two boys and the needed space is perfect when out all day. I had a hard time getting stuff out when the 19 was packed to the gills.
Also the dyneema is ridiculously good looking (quoting zoolander ), Lightweight and weather resistant (snow, dirt etc).