The one thing that comes from a proportional representation system is that you're less likely to have majority governments, and that's its major criticism.
Single-member plurality systems create majority governments, and most people will say, “Oh, majority governments are good governments.” But we've had minority governments, frequently, that have been good governments and have managed quite effectively. Sometimes those minority governments actually work better because they have to work with the other parties. They have to get others onside to support their legislation.
I think that in a system that is less likely to produce majorities and more likely to produce parties that don't quite get 50% and have to, then, work with other parties, you're less likely to attack them and be really negative to them because the next day after the election you may want to make a pact with them and work with them and get their support.
Electoral systems have all kinds of unintended consequences and can be very positive or very negative. You just have to be aware of all the options that are there.