I wish someone ran a proper study. In my experience it helps mark some patterns you may not be immediately familiar with, like CRC functions/tables. It also does a good job where no thinking is required, like when you have partial information: "for(unk=0; unk<unk2; unk++) { unk3=players[unk]... }" - you know what the names are, you just need to do the boring part. For completely unknown things, it may get more interesting. But I know I'd like to at least see the suggestions. It's a long and boring work to decompile things fully.