My current and previous pairs of glasses are/were Transitions. There have been changes in Transitions in the past few years (according to our Optician). I can tell that my current pair gets darker, and quicker, than the previous pair. There is a teeny, teeny, teeny tint when inside, but we REALLY have to look for it.
They don't get very dark when in a car. DH wears actual sunglasses when driving, but I don't.
This is the first pair of Transitions for DH, he got them because they were only about $20 more in a package that included what he was going to get anyway (anti-scratch, non-reflective.....)
Since we have 300+ days of sun here, it really has been nice not having to change from sunglasses to glasses (and vice versa) going in/out of buildings. I do wish they got darker in cars (they DO darken, I just want darker).