I share your pain on the trial/error method. As usual with these issues, there a gazillion variables, not the least of which being personal preference, climate and application. For SRT Missions I GENERALLY prefered LBE vests or, depending on my assignment sometimes the classic LABP Point Blank Ballistic LBE Vest.
But you've got to remember, USUALLY, those are very short duration operations. Take a look at how much of your upper body is covered by that kind of gear. It is streamlined, but it covers a whole bunch of the surface area of your torso. Which, if it's 30 degrees outside and your essentially going to assault a single family dwelling, you get some insulation while your positioning for the assault, and usually it's over with in 20-45 seconds before you're "Code IV."
Conversely, if it's 100 degrees outside and you're mission is more of a military orientation, I definitely prefer the old fashinoned military web gear with the Vietnam Era "H" suspenders. Packed pouches on your belt and in your butt back aren't obviously as streamlined (advantagous in moving through doors and hall ways), but a enormous area of your torso is exposed to dissapate heat.
So in "my world" there is no "one size fits all." Both systems are great. Vest wise, you're probably in the ball park for having a pretty effective set up. For field deployments in desert summer heat, I'm going with the proven old "stand-by" ALICE gear, and leaving the kevlar, ballistic ceramic crap in the truck.
Just something to think about?