A follow-up on my specter post: you can comfortably fit 2 half cubes in the main compartment and not cut into the end compartment space where another half cube can fit. I have 3 days left to practice pack before the real deal. Looking forward to braving the ATL layover with the NFTD. I can't tell you how many times I've had to run in this particular airport, or walk to the completely opposite end.
In another post (@moriond help me), someone questioned why you would need the entire arsenal of TB. Well, sometimes I go to conferences sans computer (WF), other times it's BYOD for presenters (TS), and sometimes you have something oddly sized and really need to bring out the big guns (A45). In this case, it's a summer trip and it's easy to travel light. Most importantly, it works for me. If you don't travel a lot or always take the same type of trip, maybe you do only need one bag. But there's a certain flair in knowing these bags inside and out and choosing the one(s) that compliment your journey. The same care and thought that went into the design and production of each bag goes into my consideration of which bags I want to own and use.
Just my two cents.