Yes speaker placement is important. No Audyssey can't fix "everything", but with the 3808 Audyssey will adjust the sound you hear from the places your speakers are so that saying it "sucks" is probably not the case.
It isn't as hard as many of these posts seem to imply. You go through the Audyssey setup, tell it how many speakers you have, size, etc., and let it test, adjust and set the playback so that it will sound pretty dang good. It will make the most of where your speakers are.
In other words let Audyssey do its thing and then judge whether or not "sucks" is an accurate descriptor.
E.B. White said, "I arise in the morning torn between a desire to improve the world and a desire to enjoy the world. This makes it hard to plan the day."