This is my first time posting. I was intrigued with this question and read many of the posts.
Here's my take:
Olive oil (EVOO) is great when used for dipping or adding to other dips (hummus; baba ganoush) and for some cooking. It is not great for ALL types of cooking. For example, in my opinion, it does not do well with Indian cooking. Nor is it great for frying anything due to its low burning point.
My in-laws bought a huge jug of olive oil from Costco. They were using it for all their cooking. I noticed that the food tasted different -- it wasn't great -- not what I was used to. This happened on a few occasions. I was asked to make something while I was there one time and noticed the olive oil. I searched for anything else; vegetable or canola oil. Nothing. So I was forced to use it and my dish, which is usually really good, tasted like @#$%. Even my kids complained that there was something different. Maybe the in-laws don't feel the difference because they are older and their taste buds are changing?
Time passed and we were getting together with a lot of family members at the in-laws. My hubby asked me to make this wonderful fried fish (Indian style) that is only known to a particular region of north India. I carefully prepared it and marinated it. I thought that I would fry it at the in-laws so that it would be fresh and hot. My husband bragged about this fish. I started to shallow fry it with the olive oil -- I thought they might have vegetable oil by now. The fish started to cook really fast and the inside was too wet. I had to really fry it to get it right. My husband complained that it was not as crispy as he likes it; that his friend could make it better! The nerve! I struggled to get it right and was stumped as to why it was not up to par. Then it hit me -- it was the olive oil. I told my hubby though I'm not sure he believed me. It still tasted great but that was thanks to the spices. I told everybody that the fish tasted different because of the oil.
A few days later, I made the same fish at my house. I used vegetable oil. Wow. What a difference! The fish was back to my standards. I made it to prove to the hubby that the oil makes all the difference. He finally got it. I swore that if he ever wants me to make the fish again at his parents I would either fry it at home or I would take my own bottle of vegetable oil with me!
Thank goodness! My in-laws have started purchasing vegetable oil again. They still use the olive oil but at least there is vegetable oil.
Oh. One more thing. I ran out of vegetable oil once and use olive oil for making rice. Since you really don't need that much, I thought it would be fine. What a mistake. My food tasted horrible. To this day when I think of that rice I seriously gag. I'm actually turned off by rice now because of that one mistake. I should have just boiled the rice that day. I'm not crazy about boiled rice but at least I would still like it today.
Anyways, sorry for the long post but I thought I would really relay my experience.