As for the value of tungsten versus not, I chalk it up to fluorocarbon versus not. The simple truth is there are variables that we simply will never fully be able to account for.
@triploidjunkie doesn't use tungsten and catches big fish, but also fishes where there are big fish and quite likely could do better with tungsten in the right situation. But why worry about it?
I like to eliminate variables, but I'm also cheap. I use fluorocarbon and tungsten on the regular, but have seriously wondered more about my tungsten than my fluro because fluro seems more regulated with dimensions than tungsten with weight. I 100% agree that tungsten beads should be measured by weight as well as size and I've noticed the difference.
The problem is, that you can buy cheap and get good quality and you can buy expensive and not and that can freaking change, which is super frustrating. Ultimately you have to experiment to find what works for you.
If you find a company that is willing to work with you in quality, go with them. In the long run that will serve you well. Honestly, I'm still experimenting with companies. I'm still not 100% sold on the quality/cost ratio yet.