Lily, I'll hit L103 next week and will probably spring for the new driver just to have a 9 degree R1 to go with the 8 degree R1. I don't expect it to shave strokes off my scores, just looking forward to a new toy/tool to have in the box.
As far as the meter speed, not sure why it's so much slower and don't really know if it'll be a problem, but not too worried about that.
I agree with Siggi...get it just because...mainly because if you pass on the opportunity, that little voice will be saying, "Why didn't you get it when you had the chance???"
That journey from L100 to L103 is a looooong one for sure...L103 is 3,024,740.
btw you're gonna love the L100 irons. :-)