I used to be a big fan of proportional voting systems but seeing how Israel might have something like 5 elections in about two years, and just can't manage to create a government just shows that having "too much" proportionality can be a problem too.
And mixed member proportional representation does not solve the underlying problem since it just allows part of the representatives to be locally elected but at the core it's still almost entirely a proportional system and it looks like several parties can really game the system like in the recent Scottish elections where some indepence parties were trying to artificially increase the representation of indy voters by only (or mostly) running list candidates.
While being 100% first past the post is terrible for reasons that we all know, I do think that bigger parties having an advantage over small parties (but without being able to just wipe them out) is good. My best combination would be half of the seats being filled through instant-run-off voting and the other half proportionally (open or closed list, I'm not sure which is better just yet).
By the way, this is what I'm talking about:
https://en.m.wikipedia.org/wiki/Parallel_votingThoughts?