I had a great guy when I bought my BMW back in 2008. I had done my research. We both knew what money he and the dealership was making off the deal. I was fine with that. I don't think he was typical. So, in the end, I think a great dealership with dedicated professionals is better than mail order and that mail order is better than most dealerships.
But then, I'm a guy who buys plenty of stuff on Amazon, but at the same time regrets that a great little local bookshop has died (even though I tried to get my books there).
What can I say... I leave a conflicted life.