As far as I'm concerned, these 3 items are must-have safety items (along with the knowledge and training on how to use them correctly--esp. beacons) if a person or group plans on venturing into the backcountry where avalanches are a possibility.
So performance and reliability would conceivably take precedence over weight where life or death situations are concerned.
But that said, certainly there are backcountry safety items that are lightweight as much as they are reliable and effective (???)
So, a simple question I'd like to throw out for discussion is, what's your lightweight (and/or compact) shovel, probe and beacon solution? As always, brands, makes/models, weights--or links to said items--would be appreciated.