I have only ever ordered from classicparts. They have good customer service. Prices are great and quality is good. Except I don't know much about their metal, I don't deal with repro metal anyway. They do charge 10% of order shipping, so if you order 100 dollars worth of product your shipping is $10, kinda good, kinda bad. I have spent alot of money on shipping.
Their website is the best I think. I love their catalog too.
But I am definitely believe every distributor prolly has a pro and con.