I have a MBP 17" and a 13" MBA. Boot times on the MBA are a lot faster obviously, and file save operations or anything that requires a read / write to the HDD / SSD is faster on the MBA.
However, my MBP (17" OCT 2011) is the main workhorse for portable computing for several reasons....First and foremost is real-estate...The 17" screen is a joy to use...And secondly, storage. The MBA with it's 256GB SSD just does't have enough to be used "Stand Alone" at least, not for my purposes.
I love both of them, but if forced to part with 1? It would be the MBA, it's more my "Fun" machine, not for games, but for late night in bed web browsing, etc. It's great...I do a little light photo editing on it, but the GPU isn't up to gaming either if that's what you want to do with it.
I'm lucky to have them both, but the MBP comes out on top for me, It's big and heavy I know, but it's a great workhorse.
Best way to decide is to go to a store and get hands on.
