I would say it's primarily precision and spin. It's hard to quantify because the ratings (1-5) are just estimates, and some are flat out wrong. You mentioned that meter speed is important to you; the Vokeys are much slower than their 3.5 rated meter speed would suggest. They play closer to 4.0 or even a touch slower. Unfortunately, you really won't know for sure what you like the best until you try them all.
Even if you build a set around a 4.4/4.5 meter speed, I would still recommend the Vokey 64° (60yd) for your shortest wedge. The shortest Callaway is rated at 75yds, and that's just too long to be consistently effective for shots under 50yds. The shortest MAX wedge is inferior in every metric to the Vokey. And neither is available until you get into the 90s levels.
You can buy all the Vokey wedges at L80. You won't ever need to upgrade wedges again.
I've played them all. I find I have more control with the Vokey 64° wedge on all 5 shot types than any of the others.
The longer wedges are a little more difficult to rate. I prefer the Vokey 60° (80yds) to the Callaway 60° (75yds). But I prefer the Callaway 56° to the Vokey 56° (both 100yds). You just have to play them to know what suits you best. After you get to the 90+ levels, keep an eye out for free rental weekends and try the Callaways and the MAX wedges for free. You'll see the differences pretty quickly. Until then, the Vokeys are your best bet by far.