Got the "full package" about 6 months ago.
I use it when treking along park & remote wilderness trails mostly. It keeps the camera VERY secure against my body when I'm climbing & jumping over obstacles on the trail. I've done walks up to 34 km with the rig on (D700 with grip & 70-200mm f2.8) and never even noticed the weight of the camera & lens - not so with ANY neck/shoulder strap!
It's great for cold weather shooting too as it keeps the camera body close to your body, and therefore keeps the battery warm and working.
If your camera has a grip on it, make sure to order the angled version of the holders - they angle the camera down (into your chest) so the lens contacts your body too.
Finally, I don't use it 100% of the time - just when I'm out doing longer treks (longer than about 5km). I still use the good old UPSTRAP shoulder/neck strap for day-to-day shooting and short treks.