Wouldn't do it even if it took only 2 seconds. Most of the time I'm travelling with family, and thus don't have time to keep changing lenses as well. Also, being a klutz I am, I would have the tendency to drop the lenses during the change, so I'd rather not take the chance.
Hardly a bar of gold, really. Got it for effectively €400, but all the more reason to treasure it since I can't afford to pay the original price!