I use the LVL97's. I rented the LVL100's once, & hated them. The 4.4 to 4.0 meter speed seemed like a huge difference, & I just couldn't get used to them.
The 4.4 meter speed also matches the LVL99 3-Wood, and is essentially the same as the 4.5 drivers & MACK Daddy wedges.
If you use expensive slow meter balls on a regular basis, then the LVL100's might be slightly better.
But if you use cheap-mid range balls most of the time, the LVL97's are the best. I'll take the the roughly .5 meter speed over the .5 forgiveness any day, as better meter speed IS essentially more consistent forgiveness.
The .1 more precision was probably tacked on to the LVL100's to make them appear "better", though it has no discernible effect whatsoever.