I've never had a problem with Amsoil. I have, however, have always had a problem with the way it is sold. Usually by some guy who searched for the word "oil" on all kinds of forums and then tells you how great it is and posts a link to his site that sells it.Myth: Use synthetic oil and you can not go back to conventional oil. Fact: you can go back to conventional oil. Both synthetic and conventional oil have to meet API service classifications. Also both are SAE (society of automotive engineereed specific oil). If you use a really good synthetic like AMSOIL the benefits are many, like reduced engine wear, cooler engines temps, cleaner engines, better fuel mileage, saving money with extended oil drain intervals. Why would you want to go back to dino oil? Spend more money with conventional oil or spend less money for oil changes with synthetics. Oh by the way synthetic oils are not created equally most are hydro-cracked petroleum oil like everything on shelves at auto parts and walmart.
If you want to spend your hard earned money on just mediocre synthetics then they are widely available. I am one that doesn't mind spending a little more for a superior product most times.