Is the answer 42? I remember looking at some different forms of voting systems that were proposed by the Labour Party in the late 90's and whilst all had their merits they all had drawbacks and witnessing at counts the difficulty some have with putting one cross in a box my opinion was to keep it as simple as possible. I believe there is still plenty of merit of having a directly elected MP who represents and is answerable to his or her constituents but the First Past the Post system is unrepresentative of the total votes cast. A recent example of unfair representation was in 1983 when the SDP/Liberal alliance won 25% of the total vote and only won 23 seats whereas Labour won 209 seats with 27%. The Scottish parliament is made up of both constituency MSPs and MSPs off party lists depending on the share of the vote covering a region. I'm not too sure about having a mixed chamber as there is distinct differences to the type of representation that is expected of the MSPs. Having two chambers can accommodate both types of representation but which chamber would have the ultimate say on matters is another matter.