Personally, I dislike MMP, because it is a such a mishmash. I especially dislike the system Wales uses, because it is not proportional - it has 2/3 constituencies and 1/3 regional top-up, rather than 50:50. I would prefer a strictly proportional system. There is nothing that prevents multiple MPs having a constituency link, and such constituencies would be built on far more "natural" communities, instead of arbitrary slices of cities or rural constituencies that are designed to fit a specific amount of population. Indeed, the "constituency link" is a relatively recent thing for MPs in the UK.