The reason you don't really see a test of all three against each other is because the only fair way to do it is to compare all three systems on the same car. The health of the other components in the braking system is a huge variable. Some people will say their vacuum system won't hold 2 psi at the line and they will blame it on the type of system rather than investigating other components. There are plenty of people who have great success with ANY braking system because they do it right.
Just my opinion...
It is agreed that vacuum is the quickest and easiest and can be just silly cheap if you source used parts as noted above. Would I put used parts in? Probably not, but that's my personal preference.
Hydroboost is a challenge, but the parts are easily sourced. You just have to be ready to deal with the shortcomings of a stock TR system, most notably the lack of an accumulator. If your engine shuts down, no brakes. There are aftermarket kits that have accumulators but they can be pricey. You can also look at systems for other vehicles that include an accumulator, like the Chevy Astro van. To give you an idea of price, a complete system will run you around $325 for remanufactured parts specified for a 1984 Turbo Regal.
I think if I were you and you just want your brakes to work, I'd replace the ball and change the fluid every year or so. Keep it clean and it will reward you. Powermaster gets such a bad rap.
Why did I change to hydroboost? I drove all three examples in similar cars and chose hydro for the pedal feel. I didn't care about stock appearing and I wanted a nice project to occupy some summer time. With no other changes to the system, I can say that it improved my braking quite a bit. Can I quantify it? Nope. Can I feel it? Yep.
