Continental Europe (the UK uses FPTP) is characterised by countries that have governments that are frequently deadlocked or missing in action, because proportional representation results in lots of parties getting into power with none having a majority. Therefore they spend lots of time building coalitions that can agree on very little except preserving the status quo.
These coalitions often result in absurd political configurations, like alliances between parties that are supposedly of the left and right, resulting in an inability to create policy. You also see bizarre compromises that can cause extreme or weird policies to appear that hardly anyone would have voted for, due to the need to bring on board smaller parties to make the coalitions work.
A few examples: in the Netherlands, the ruling coalition has a working majority of 1. It contains many tiny parties and took months to create, because they were determined to ensure that the politician who runs the second largest party in Parliament (Geert Wilders, who is anti-EU) would be entirely frozen out of power.
Germany is ruled by a coalition of two parties that both lost votes in the last election, and whose leaders hate each other. They both believe repeating the same coalition again will severely damage both parties, as it's a coalition of both the left and right meaning ... again ... essentially the coalition has no coherent policies that anyone campaigned on. However they did it anyway to freeze out the second largest party, AfD, again because AfD is anti-EU and that is seen as so bad almost anything is worth it to avoid having to compromise with them. Before the current coalition formed, Merkel tried to create the "Jamaica coalition" ... a truly laughable attempt to break the basic laws of politics by uniting the far left Green party with a libertarian party. Not surprisingly the quasi-communists and Ayn Randians couldn't agree on anything and that attempt failed, but it goes to show how strange proportional representation can get.
Italy has just voted in a coalition of two parties, again, a left and right wing party who have, as a result, economically incoherent policies. The "right wing" party wants devolution of power within Italy and more regional self rule, the 5-Star movement wants the opposite, with more subsidies for southern Italy.
Basically PR gives you messy governments that frequently collapse or deadlock. This may or may not be a better arrangement than FPTP which tends to yield strong governments with clear policies, which frequently see-saw between polar opposites as left and right parties take turns in power.