Overnight bag for 2
I am looking for an overnight bag the would be big enough for 2 people (my wife and I). I am thinking the western flyer should be big enough, or would this be overkill. The bag would be used on weekend trips (2 or 3 days). We usually take a couple of days worth of clothes, toiletries, etc. Do you think it would be possible to also fit my 17" macbook pro with a brain cell along with the 2/3 days worth of clothing (not having to carry a separate laptop bag would be a bonus)?
You are out of luck on the 17" MacBook front. The 17" MacBook will need to go inside a Size 1 Brain Cell, which does not fit into the Western Flyer. It would, however, fit inside of a Tri-Star.
As far as your 2x 3 changes of clothing and toiletries, I believe the Western Flyer should be up to the task however it would probably depend on the type of clothing (heavy trenchcoats, fur coats? likely not. t-shirts and shorts? definitely! blouses and khakis? likely doable) etc. Also are you planning to pack shoes into the Western Flyer?
Personally I think the Western Flyer might be a bit snug for what you are looking for, especially if you are going to do more 3 day trips thann 2. The Tri-Star should work pretty well, and if you want more room you could consider an Aeronaut, which would give you room enough to easily divide your stuff.