I've just taken delivery of my Ristretto for the 13" MBA and already love it! I will be getting a LOT of use out of this.
The only thing that concerns me is that when the bag is clipped closed, it would be very easy for pickpockets to slide their hand into the front cut-away compartment and help themselves.
The small pockets sewn in there are obviously designed for gear like mobile phones, and the whole area is a handy size, however I feel very wary about having anything of value so exposed. Clearly you don't HAVE to put valuable items in there, but this is such a good bag for tech gear, it'd be a shame not to get the most out of the space.
Does anybody else feel like this, or am I just being paranoid?