I've never ordered a saddle, but I have ordered several other things.
Service wise, they're always quick and well priced to ship.
As far as the saddle, that depends on the brand itself. Stateline has downed their quality on some tack (like bridles and saddles), although they do sell a couple nice brands still.
Just know your brands well, and figure what size and everything you need. Stateline is pretty good on shipping, so returns aren't a problem with them.
"You're just as sane as I am."~Luna Lovegood.