As you can tell, I'm a big fan of not only Thinktank bags, but especially their rolling series, which has literally saved my back, and the backs of many photographers globally. I think if it wasn't for these bags photographers would be retiring much earlier than they'd like. Shows, it took photographers to make these bags to understand what photographers really need.
I've been using these bags since they were first launched some 7 years ago. Since then, they have stood up to everything I have thrown at them, and most importantly, kept my equipment safe in the process. They're designed to look simple and clean yet elegant. They are very practical with plenty of storage pockets and combine the perfect balance of protective material to space ratio. They're also quite light given their quality, which means you can take more gear with you when traveling.
I don't really like carrying shoulder bags but when I do, I use this small bag for my Leica M. It's very discreet with no obvious labels and plenty of small compartments, lacking in other competing bags. It has just the right amount of padding without being 'too' padded and bulky.
It has two zippered compartments - one inside and one outside that are great for securing small items like valuable memory cards and passports. It's great for carrying a rangefinder-style camera and a couple of lenses and kick-knacks. It's quality is fantastic so don't even think to question it's price. Definitely my favorite shoulder bag for the Leica M or any small camera.
I cannot recommend Thinktank enough. They have bags for any kind of photographer and their service is also equally impressive.