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From those 3 choices, I'd put my money towards the Brenthaven. I don't have any experience with any 3 of these bags, but generally Brenthaven makes some high quality products, albeit at a high price. However, since the pricing seems to be the same for these 3 bags, I say go with the Brenthaven Fusion.
 
Well, I've used a Commute for a few years now, and it ket my Powerbook safe and dry all the while. Great bag, great for walkin' around and bikin' and such.
 
I have a Brenthaven Fusion (for a 12" notebook) and I think it is a good shoulder bag with nice padding inside and on the shoulder strap. I also have Timbuk Computer (for a 15" notebook); it is also a nice bag as well. Since I don't take a 15" notebook out, I don't have an opportunity to use that bag so far.
 
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