I think REI is the way to go, since E is "sigterm" (i.e., "kill -15") and
may meed to write additional data to a disk... It's also important to note,
one should not just fly through the letters, again as "E" is asking for a
nice shutdown of processes, and S is writting everything in cue (as I
understand it), this can take a few seconds to complete.. You can keep an
eye on your HD blinky light to know when its safe for the next letter.
Someone correct me if I'm off base here...

you have to go through the REISUB slowly, on my laptop I
have to hold Alt and SysRq with my right hand while typing the REISUB with my
left.

That's pretty much the way I was thinking, too. I was just wondering if
there was any reason why some people go for RSE instead.