Point taken for disrupting the thread, sorry 'bout that, md.
My point to you, SJ, had a lot more to do with dirty gear and sub par pics than you realize. You are right that they don't appear that great as a selling point to customers but that wasn't what I was going for. A production climber has dirty gear because he uses it and photos are generally an afterthought not the main goal. But let's talk about that lanyard of yours.
TheTreeSpider is a published author in our industry as I assume Tom Dunlap is as well ( I've sure heard his name kicked around enough ) and I have no reason to disrespect their work and can only assume they know a hell of a lot more than me about my profession. Their names attached to a product will get me to look closer at it but their assessment of said product will not be the sole basis of my assessment. I look at the piece of equipment and form my own opinions based on my personal experience and what I know that my profession demands of it's gear. So let's have a look again.
You claimed in your first post about this set up that it " uses less hardware " than two separate lanyards. However this lanyard uses two rope snaps, two clevises, two friction hitches and a very long piece of rope. A conventional lanyard set up uses two rope snaps, two 'biners ( or you could put clevises there if you want it permanent or even tie your lanyard to the D rings for more permanence and even less hardware ) , two friction hitches and some rope. One could very easily make 2 lanyards out of a 21 foot piece of rope so we'll not count that as additional gear on a two lanyard set up. Not to mention that the rope that you loose behind your back is not part of the "workable" length of the lanyard. Assuming that stretch of rope behind your back is about 24 inches you essentially lose that amount of line. Boom. Added weight.
Now, the one benefit you did mention was that "virtually all lanyard length is available from one side." This indeed is a good benefit. With this set up you can have one lanyard very long and one very short which would be helpful in some positioning situations but it begs the question why not just carry one long lanyard and one short lanyard with you on the climb? They weigh less, as I already outlined, and it gives you the option of leaving one on the ground if unneeded on the climb.
And my final point...loops, loops, loops.
As any production climber will tell you getting stuck on a branch or nub is a frustrating, annoying and downright dangerous situation. The more loops you have the more chance you have for them to catch on something. A loop of lanyard hanging down on your saw side is sure to entangled with your saw at some point during the climb. I've had webbing loops slip around my feet from time to time when twisting and stretching for a certain position. I've had loops from my saw lanyard hang up on nubs and stop me mid swing. The list can go on and on about how loops of rope can get in the way of an efficient climb.
So, in closing, I've determined that your two so called benefits are not realistically beneficial and moreover, the entire design is a hazard to a productive tree climber.
THE END