In answer to the OP, I've had the Versa since level 70 and really like it. Whilst I'm nowhere near a "top" player, I'd say my putting is a bit ahead of some other elements of my game (eg off the tee, or scrambling yikes), and the Versa does a really good job. I can't blame many misses on the putter, to be honest.
Going up through the lower level clubs, I sort of weight Forgiveness, Precision, Balance, etc all equally. My view was that a club that gave me more good stuff overall was better, almost regardless of what it was.
The meter speed, though, is a priority to me. Having clubs with manageable and ideally consistent swings seems to really help with my timing. A stick with superb precision that I can't hit right is just going to hit superbly precise misses for me.
I've certainly heard it said there's almost no need to upgrade from the L70 Versa, and so far I've not unlocked a club that I feel compelled to get to replace it. The L98 Sabertooth (RIP) did seem to have it covered in all respects, so that was my planned future putter... now I guess I will look at the Red Spiders - if I ever get there.
As to what the different elements DO, I had assumed it was something like:
Precision - how far off where you aim the club will typically hit. Higher precision equals smaller random variations.
Forgiveness - how far off line from your aimed position the club will hit depending on whether you ding or not. Higher forgiveness means an off-ding is more likely to go where you aim (within random variations).
Balance - how far off the distance you selected on the meter the ball will role. Higher balance means on a dead flat green the ball will roll to a distance more consistent with what you hit on the meter with lower random variations.
Clearly the common thread here is random variations. To keep the game feeling vaguely real and challenging, every shot has a fudge factor to represent the infinite variables of the real world. Which of course creates situations where you can mis-aim, mis-hit, and still get it in, where random variations cancel each other out or (wonderfully) correct your mis-aimed shot.
tl:dr L70 Versa is a good putter, there are other good putters, if you want to get really good you will have to practice and calculate - but I can't be bothered doing that.