Not sure that they adverts are anything but adverts for one makers rather over engineered strap... I carried a general purpose .50cal machine gun in days of yore that didn't have that amount of strappery!
Seriously though... I do wonder some days when I see folks out with their Rebels and smaller Nikons etc hanging from a strap, either at the camera makers mounts or from one of these straps that fit the tripod screw fitting in the camera base, over their shoulders with the whole lot swinging about... and have seen many times when the lens barrel contacts a person or a more solid wall, car etc... Why would you not want to keep the lens safe? Then there is the issues of such cameras... any really, with even a 20-200 f2.8 fitted... that weight is being supported at an acute angle by the camera body and its attachment ring....
Then, there is a whole body harness... spend a while to get in it and have your camera hanging in front of your chest... great but the lens is still hanging unsupported...
So, is it a decent strap you need? Or, you want to be comfortable? There are straps such as the one I have used for years... the OptechUSA... a neoprene and rayon wide strap... takes the pressure off the shoulder for smaller lenses and keeps you in contact with the camera... same strap if I have the 400 f2.8 but now I cradle the body with the lens facing up in the crook of my left arm... still got physical attachment to the camera... but supporting the lens and critically, it's mounting ring with all of it's connections to the body. No pressure on the neck... carried in arms... I, like EnglishBob, and doubtless many others, carry 2 cameras... one with the wide angle - I carry that with the strap over the opposite shoulder and pull it round so it is on my back... and the longer heavier lens cradled and ready...
I do understand that for some weight is an issue... however you carry it... it weighs the same! You even increase the body load with some exotic harnesses ... like the Cotton Carrier Camera Vest w/ Side Holster for 1 or 2 Cameras - it claims, as they all do, to reduce neck strain... might well ... at the expense of shoulder strain... these are like a loaded rucksack carried backwards! And this model is a $199 cost! That's an expensive strap... not to mention what you look like...
If you are going to carry a heavy camera or cameras around for a day... plan for it and it's not the cameras or the lenses you chose fault for being heavy... so you need to look after them not fob that responsibility off to a third party manufacturer and complain later the harness made you sore and your camera got in the way of a parked car...
That all said, I will quote EdMak... "to each, his own"... end of the day, what you suspend your camera and lens with is your call.
So, food for thought? Anyone any other ideas? Maybe there is a panacea out there?
Kind regards
Rolf