The Creature Collection Revised was, to my recollection, actually being written before the revised 3rd edition announcement was made. It was just delayed and re-written again for revised 3rd edition once Sword and Sorcery was given notice of the up-coming revision. Minor point, but, there you have it.
As for the original Creature Collection, eh...realize it came out about a week before the Monster Manual hit the shelves. It has a number of problems with it. Even if you're not going to play revised 3rd edition D&D, you would probably still have an easier time of editing the Creature Collection Revised for yourself than you would the original Creature Collection. The Revised one, at least, has a better grasp of mechanics, balance (the original Creature Collection had a few way off-base Challenge Ratings), and the like.
For that matter, unless you're going to play in the Scarred Lands, due to those errors in the book, the first Creature Collection really isn't such a hot buy. You'd be better off with the Tome of Horrors or possibly the Monsternomicon (though I'm inclined to say that as generic fantasy monster books go...it's, well, pretty terrible. Not because the ideas and the balance are bad, just because a lot of it isn't what I would drop into just any D&D campaign).
All in all, I'd say go with the Creature Collection Revised and if you're going to play in a normal 3rd edition game, just alter the material from that book, instead of using the original Creature Collection.