The Catapult Cycling Messenger Bag is available in 2 sizes, the medium and the large. For the medium, there are 5 designs and for the large, there are 3 designs.
Since I already have a Custom Laptop Messenger Bag (Small) and I am not a fan of big bags, I chose the Custom Classic Messenger Bag (Extra Small) which fits an iPad.
Bought the Timbuk2 Custom Laptop Messenger Bag from timbuk2.com when they are having a 20% off custom bags from 5th to 8th March 2013. I placed order on the 6th March 2013, my bag got shipped on the 12th March 2013 and I received it on the 18th March 2013.
Paid US$119.20 for the bag and an additional US$15 for the Navy Custom Strap Pad. Shipping via UPS Worldwide Expedited is an additional US$30. After the discount, the bag comes up to US$164.20 (S$205.30)
I got the Timbuk2 Command Messenger Bag (oxford nylon black in medium size) when I was in San Francisco back in December 2011. It was retailing for US$130 which after 8.75% California tax comes up to US$141.375 (S$176).
This bag is Transportation Security Administration (TSA) friendly in the US because the laptop compartment can be unzipped separately to flatten the bag for it to pass through the X-ray. In this way you do not need to take your laptop out from the bag. I have not tested this in Singapore Changi Airport yet, but my guess is that you still have to take the laptop out from your bag.
Received the Timbuk2 Freestyle Messenger Bag for iPad from my brother as my birthday present last year. I think at that time it is retailing for US$89 (S$111), but it is on offer now, timbuk2.com is selling for US$54 (S$67.40).
Despite it is a bag for the iPad, it is able to fit in a 13″ MacBook Air at the main compartment (not the padded iPad compartment). I am guessing a 11″ MacBook Air should be able to fit in the padded iPad compartment.
I think I just become a fan of Côte&Ciel bags, their bag design is unique and nice. If you want to get their bags in Singapore, you can check out Cumulus at Wheelock Place or their online store cumulus.sg.