The bounty battles and Piastol were good addons appart fromnew discoveries.

is worth a try 

Skies had far more moments of "awe" to me.

Getting the harpoon canon, then the Delphinus, then your own island, Racknam, casting Prophecy, etc...

BK voice acting was horrid, I turned it off in the first half hour. That option to turn it off saved it for me, I don't think I would've stuck with it if I had to listen to that the whole time.

I need to get origins, I never played it.

 I hope I like the game if I ever play it as I heard it is really good.

Hmm..I'm still not sure. Baten Kaitos is cheaper and graphically better so I'm leaning towards it.....is the gameplay in Skies of Arcadia good or what?

For RPGs I guess I don't mind battle repetition I guess, as long as its good. I kind of recently beat Legend of Dragoon after 65 hours of battling and doing MADNESS HERO!!!

I haven't played SoA, but BK has one of the greatest storylines of all time, in my opinion. There is also so much to collect in BK that it is probably impossible to get everything (given that a great portion of it is one-chance collectables). I would say it takes about 50 hours to complete.

 BK's stories is standard RPG fare with the exception of the 'plot twist' which just happened to be well executed

The battle system of SoA is unique, and its very satisfying.
You battle as a team on the ground and on your ship and you also get engaged in ship battles where you get to fight ships or giant bosses. Story is epic and its perfectly ambienced.
As well as upgrading your cahracters, you need to upgrade your ship with new and better parts.
A masterpiece IMO.

Same with Skies.   I've played through it a few times and it's taken between 55-70 hours to collect aboslutely everything.  The good news it it is all worth collecting as you are rewarded for your efforts...unlike some games.

Wow. I wish I could get both, but that's like a $40 combined purchase....and I'm a wee bit too young to work....hmmm...I'll probably get BK first.