I'll just give you my impressions of that. I imagine that voters represented by people who have a greater weight to their MP's casting ballot will feel empowered, yet voters who have an MP representing them who's at 0.7 of a vote will not feel as great.
I know the goal you're aiming at. At an intuitive level, I could imagine people standing in the House of Commons and I could imagine voters saying, “You're my MP. I want you to vote this way.” Elizabeth has 12 votes, I have 0.75 votes, and yet we're still members of Parliament. It feels odd, I guess.