I love RPC; it’s much better utilization of pins - same bandwidth over 22 as over ~ 45, IOW about twice the bandwidth per pin. Downside is a slightly higher latency because address and command have to travel over them too, but this is amortized over the burst transfer.

The real problem with RPC is that devices has tiny capacity; 256 Mb today and max spec’ed to 8 Gb (yes, I am aware that they consider it a feature, but I don’t). Also, it’s actually pretty expensive today compared to regular DRAM.