Not CT, but I'll offer my two cents.
Hanging the weights on bands or chains will be hugely different to using a cambered bar. On bands or chains, the weights will swing in all directions making the exercise one more focused on keeping the bar stable. With a cambered bar, all that changes is where the weight is compared to a standard bar - so it emphasises different muscles or weak points within the exercise but won't make the main focus keeping the bar stable.
In terms of camber length it depend what you want to do I think. For squatting, the longer the camber the further forward it shifts the weight. I think for bench, it just makes the weight sit lower.