Well I have had my Think Tank speed belt and modular set for about six months now - and about two weeks ago I got the complete Cotton Carrier system and thought I would post my impressions on the two.
Think Tank Speed Belt and Modular Set and Pixel Racing Harness:
Purchased from Borge's Imaging in Melbourne as they had a healthy selection of stock.
The belt is well padded and adjustable- just be sure to get the right size as it is not one size fits all. The Modular set consists of a number of pouches/compartments that attach to the belt with velcro. There are plastic tongues on the modular pieces so you can choose to have them fixed in place or free to slide around on the belt. I find the latter much more useful as it allows you to shift stuff around when you need to crouch, lie on your stomach or manouvre in cramped quarters.
Like all the TT stuff, quality is top notch and every piece has its own raincover. In hindsight I think I would much prefer the Skin set -which serves the same functions as the Modular set but basically does away with the padding to minimise bulk.
Putting all six modular pieces on the belt is way too bulky for me - it basically takes up the whole length (I'm a 34' waist) - so you can't shift the pieces around like I mentioned earlier. I usually have 2-3 components on the belt. The Speed Changer - which basically holds batteries, the Pixel Pocket CF card wallet, microfibre cloth, flash gels, phone, keys, business cards. If you really wanted to you could shove three speedlights in here at a squeeze, but it is quite heavy, bulky and yeah, who needs to carry 3 speedlights on their person? The other 2-3 pouches I use for lens obviously - I keep one empty to make lens changes quick - kinda serves as a "table".
The Pixel racing harness is usefull if you put more load on the belt and shifts some of the weight to your shoulders.
I was a bit skeptical about this product before I got it - and I still admit that is one of those "function over form" products. They now have a distributor in Australia - mine was delivered in less than 24hrs from online order -came from the Gold Coast in Qld. It costs about the same as you'd outlay on the Black Rapid Double R Strap - about $180 from memory.
If the Think tank belt modular set and harness are conspicuous - then the Cotton Carrier is probably a step above that. Its a chest harness + holster that puts the camera on your chest, lens facing down. The holster can be worn to the side above your hip, or lower on a belt - effectively carrying two cameras with lens attached.
The attachment point for the camera is the tripod socket -same idea as the Black Rapid. The mount is fairly neat and low profile and feels very well made. Mine have not come loose at all after a few weeks of use. In addition to this, Cotton have including a tethering strap for each camera which hook into D-rings on the vest. This gives you extra insurance should the tripod mount fail (unlikely), or should you fumbled while getting the camera out and it slips from your hand (more likely).
I have since put a handstrap on my D700 which helps with the movement required to rotate and release the camera, and just works well for my needs in general.
Teamed up with the Think tank modular / belt combo - you can carry quite a bit of equipment, while still having both of your hands free and not having anything swinging around anywhere. The cameras feel very secure - I'd be quite confident running full sprint (if for some reason you had to lol) without anything falling out or coming loose. The load is customised by you to be well distributed between your hips and your shoulders. I haven't used the Cotton in very warn weather yet, but on mild days it wasn't that uncomfortable at all.
As demonstrated by the photos below, it can be worn under a dress shirt for a less conspicuous look - the shirt did get in they way a bit but with practice I imagine you'd get better at it. This would also be quite hot in summer I'd imagine (undershirt > harness>dress shirt).
Anyway I have attached some (quick and nasty) photos below showing what the harness looks like and how I integrate it with the Think Tank stuff. Hope this has been helpful for anyone looking into this product.
Any questions please ask away