I've personally never had any issues with Summit. But with any company that deals with thousands of people per week/month/year, the law of averages will eventually catch up with you. When you rely on more people "in the chain" there's a bigger chance of something going wrong, especially with the shipping companies, too. As stated, the true test of a company that cares about their customer base will try to make it right when things go wrong. Any vendor who doesn't, really doesn't care and they'll never see another dime of my money when they don't. A principle kind of thing. I won't willingly and knowingly fund bad behavior (but I must pay taxes to the government, but not willingly, so....).
There's also the scammer ******* customers out there. Order a part, complain, put their used part back in the box and get a refund. Some succeed, too. What a crock. *ssh*les. Why do good people get cancer and these dicks don't?
I can also say that I've never had issues with NAPA, or RockAuto, or O'reilly's or Advance when having to order anything. Not saying I never will, but so far, so good.
I do use Amazon a lot for a variety of stuff, once I find it's the less expensive route shopping around. In fact, I ALMOST had an issue with Amazon once. It was the vendor's fault. My wife gardens a lot and she's always "losing" or breaking her little dirt digging tools. So I bought her 3 one-piece tough, polymer hand trowels. They sent 2 of those PLUS an iPhone 5 case. (We had iPhone 6's then went to X's). I'm like, WTF? So I contact Amazon on what to do next. I followed their instructions on sending back the mucked up item. They immediately credited my account right away. Kept all the receipts from the shipping and all that, got the receipt thing. Thought that was that. Lo and behold, I got an email about a month later saying if I didn't return the trowel they were going to re-charge my credit card. Blood started heating up when I read that. WTF??? I contacted them again, and then gave them all the tracking numbers and such from their return instructions, and explained how someone sent an iPhone case instead of a trowel, and that I had done my part. They apologized and said it was done. Never got bothered with it again.
And then just the other day, I ordered two of something from Amazon, but UPS had the box that arrived damaged- that's why I saw him run back to his truck and speed off. They usually ring the doorbell when dropping packages. I got only 1 of the 2 identical items I ordered and another item and some packing air biscuits. The bottom AND top of the package was busted open. But I consider it originated with Amazon packaging. 3 small but heavier items in an oversize box with a handful of air puffs. Disaster when put in the hands of UPS. Had they packed it securely, I don't think it would have happened.
But I digress. This is about Summit. When you think about it, they still have a fairly good track record of getting you the stuff you want fairly quickly. Although I realize they're probably not as hungry as they once was to make sure snafus were handled promptly.