Sorry, I disagree. Share plans are simply a way for carriers to sell the same pie for a higher price. Just give me adequate data on each plan at a descent and then there will be no need to share as if data was a scarce resource.
When I was with Rogers, they forced me in to a share plan, and I had no one to share with. Not cool! It was more expensive then what I needed to really pay. Thumbs both down on this.