Consensus appears to be that 512 really not enough, but aside from "max it out" what amounts are really needed for what activities? Has anyone run benchmarks? For general use, where is the greatest ram jump noticed (i.e., from 512 to 768; 768 to 1 GB; 1 to 1.25 etc.)? Since there doesn't appear to be any market for 256 chips (or is there), but there is for 512s, seems like starting from 2x512 might give greatest flexibility (could at least sell a 512 if want to bump).