Ooh! We had a discussion on Synthetic Saddles not to long ago! =) Oh! And it was actually posted by you, LOL! Here's the trackback if ya want it: Question About Synthetic Saddles
I would have to say Wintec for a synthetic as they aren't made with the Cordura... so they're easier to clean off =) BUT... I don't think they make 'em in round skirts for Barrel Racers, so I'd have to agree with your choice on Abetta. I owned one and admittedly I didn't like it at all because it was harder to keep clean (the cordura) and the synthetic material on the pommel was very brittle. Skippy! Fell over at the canter a week after I bought it and skinned it all up =/ He did the same with my Wintec and not so much as a scratch on it ;)
As for the leather... I LOVE Circle Y saddles, but I am unsure that they make those in round skirts either! LOL! I'm unfamiliar with the other brands ya mentioned =)
As CJ82Sky said, make sure the fit is good for you and your horse... and it would be awesome if a friend of yours had one you could borrow and ride in to see how well it fits.
Try looking at a Consignment Tack Store in your area =) that's always a good place to find good used Western Saddles.
Personally, though I LOVE synthetic... if I could get one or the other, i'd choose leather. I think they'll last for generations if properly cared for. It's worth the maintainance to me! *hugs her Stubben Dressage Saddle, as well as her Collegiate Dressage Saddle* I have my eye on a black Circle Y Park and Trail saddle to add to my collection ^^
Oop, I guess I wasn't really helpful either! LOL!
Best of luck to ya hun! Getting a new saddle is always very exciting!