Pros and cons of various sidemount harnesses, especially for cold water tech diving.

I can describe them.

1. Rather than use a bulky weight plate for the two or three blocks of lead they need, they used a weight belt bolted to both the book screws. Imagine laying a weight belt open and along the spine, burning holes where the book screws are and screwing it on. Once bolted they can thread lead onto the belt and secure it with by clamping the buckle. To avoid accidental unbuckling they put a bike-tire rubber band over the buckle.
2. They moved the shoulder straps to the back of the waist belt. So instead of an H harness it becomes more like a backplate harness (triangular, heart-shaped?)
3. They modified how the loop bungee attaches to the harness. They found that the clip and quick link restrained the loop too much resulting in the tank neck not lifting up enough. They added an additional quick link to extend it. I would have replaced the clip and link with a 1/8" or 3/16" bungee.
4. They modified where the rails attach on the back. Moving it up to the top one so they could re-clip ALs to a waist d-rings. Another burned new holes an inch or so towards the spine to correct tank trim.
5. One person has trouble with the shoulder dump. He has to yank on it far too hard to get it to activate, I've tried it and it's almost breaking force. He hasn't modified it yet, but maybe a more slippery tube or slippery pull string will fix it.
6. D-rings were added to the front of the waist belt to accommodate re-clipping ALs.

 

Every sidemount harness I've seen could benefit from a modification of some sort. I've seen a lot of creativity in modifying harnesses.