[masklinn]

> Those that get rid of districts entirely lose the ability for specific sub-regions of a state to have their own dedicated representative to vouch for their specific needs.

It's doubtful whether that still exists as anything more than a foil/justification though, given Congress's expansion was stopped a century back, and each Representatives now stands in for at least half a million people (RH has the lowest number of citizens per rep' at 530k) and up to a million (Montana, population 1042520, currently has a single rep'), with the average closing in on 740k (up from ~710 during the last census).

Can a rep' really vouch for the specific needs of 700000 people any more than a proportional delegation would?

It's unclear to me that the House of Commons manages to do that, and they've got 650 MPs for 65 million people (or ~100000 people per MP on average, though the average electorate is lower, and it has very extreme low ends, Na h-Eileanan an Iar has an electorate of under 22k).

[eli]

The people in CA-8 (Mojave Desert) have very different needs and concerns from the people in CA-12 (San Francisco) even though they represent the same number of people.

[squiggleblaz]

Actually, under Open List PR, you could still have de facto local representatives. Someone could focus their attention on the needs of the Mojave Desert dwellers and get elected or not based on their popularity in the desert. PR doesn't prevent people from focusing their attention on geographic regions; it merely creates other alternatives.