I have had a pair of the julbo magics with the zebra lens for about 4 months now. I think they work OK for glacier travel, but a buddy of mine has the instincts and he likes a darker pair of glasses for snow. They certainly are great for putting on all day and forgetting about them/not having trouble when moving from shadow to non-shadow (adjusts quickly). I agree that they don't get as dark as their other cat 4 lenses.
I was skiing there a couple days ago, tr with pics of ruth at tay:
http://www.turns-all-year.com/skiing_snowboarding/trip_reports/index.php?topic=5240.0
Glacier is a non-issue. No rope needed, no poons needed. No axe needed either unless you really want it or get there in the early morning.