Why EXT4?

Actually, I think (IOW, I'll take a decent reference saying otherwise and
learn, but based on what I've read and experience) you're wrong about
current reiserfs, altho it /used/ to have the problems you mention. AFAIK
reiserfs' default behavior is very much like ext3's default behavior in
this regard. Both of them use data=ordered by default now, and have for
quite some time. (Reiserfs data=ordered was added back at 2.6.6, according
to the best I can google, and ordered became the default either then or
shortly thereafter.) Just as ext3, reiserfs apparently doesn't have
delayed allocation, and the default 5-second-metadata-flush (which with
ordered and due to the security implications Ted Tso mentions, means data
gets flushed every five seconds too, before the metadata) applies to both,
too. Thus ext3 and reiserfs should have the same general level of
stability now, and post-data=ordered, that has certainly been my
observation -- reiserfs has been incredibly stable for me.

IOW, AFAICT, the bad reiserfs rep originates in the pre-2.6.6 era, quite
some time ago now, and it's actually a quite stable and mature fs now.
That has certainly been my experience, both bad back then, with corrupt or
zeroed files at boot after a crash pre-data=ordered, and impressively
stable, now and for several years, post-data=ordered.

Again, if you have references otherwise, I'm willing to be corrected, but
I believe reiserfs is actually reasonably similar to ext3 in this regard,
and has been for some years, now.

Duncan