You wrote: "My current glasses have a temple length of 130 and they
fit me perfectly.... How noticeable is the change from 130 to 125? "
I think it's a very personal thing. If you put your fingers at the
point where the temple arm starts to bend down and goes behind the ear
do you think that there is sufficient room there to take away 1/2 cm?
Or try moving the glasses forward when you're wearing them to see how
much forward movement you can make and still feel comfortable. It
sounds like you would notice the difference when you say your current
ones 'fit perfectly' - if they are very snug to the back of your ear
you might not be happy, I know that having the arm rub the back of
your ears is not very pleasant especially with a heavier frame. I
haven't used G4U so don't know if you get full refund if you found
that the didn't fit.