[dragonwriter]

> It comes at the cost of locality,

It need not; you can have more proportional representative in a district based system (and still also have vote-for-person), using multimember districts with a system like Single-Transferrable Vote.

You can also get finer grained proportionality with Mixed Member Proportional which combines a district-based system (either single-member or a multimember proportional system described above) with top-up representation from party lists.

MMP would require Constitutional change in the US; but multimember districts with STV (in states with more than one seat, as well as increasing the size of the House so more states would have more than one seat) can be done by Congress without Constitutional amendment.