I think it depends a lot on what you'll be using it for. We only ride on trails and we don't care about looking flashing at shows or anything like that. I bought a nice leather endurance saddle when I got my horse. Hubby bought a cheap, used leather saddle, just to get by. Now after seeing me with mine and our neighbor with his synthetic, hubby is buying a synthetic. We ride in all sorts of conditions and get pretty dirty. He won't have to spend a lot of time cleaning it and they are so much lighter (though mine isn't too bad). If I had it to do over again, I'd probably go synthetic too. As it is I never use my matching leather tack, instead I use nylon. Of course my saddle is really comfy, so I'm happy with it. I'd ultimately make your decision based on which one fits the horse better and is more comfy for you.
I was normal...then I got a horse.