Crysis -- unoptimized?

Well, now that I have a GTX 280, I tried the Crysis demo, and I'm
getting between 30 and 55 FPS on average (sometimes less, sometimes
more) with most of the eye candy turned on at 1400 x 1050. That's
perfectly playable, of course, but almost everyone these days is
looking to get more out of that title with their current rig.

It looks terrific, but what's up with this game? Are we to believe
that it was poorly coded, or is it simply such a stunning piece of
software visually that it's bound to scare the hell out of even the
most modern GPU? After all, it's not like we have access to the actual
source code, so we can't know for sure how unoptimized it is.

It's funny, because in my opinion, a game like COD4:MW (I recently
installed the demo) looks pretty much just as good, but unlike Crysis I
usually get at least 80 FPS in it, sometimes much higher (and that's
maxed out on my 22" monitor).

--
Erich K.