here's a decent article on whether synthetic oil is better than conventional oil.
http://www.msn.com/en-us/autos/owne...ally-in/ar-BBEs0Bw?li=BBmkt5R&ocid=spartandhp
now some people may just say, "well oil is oil." well, yes and no. conventional oil for the most part is pretty much the same, as it's derived in the same manner of distillation at a refinery, and one brand is pretty much the same as far as the base stock. now where they differ are the additive packages requested from one brand to the next. and those additive packages sometimes may be proprietary.
now all of this is fine and dandy, but lets be realistic. how many of us are going to subject our weapons to the same types of stresses and heat that modern engines will face in day to day normal operation? not even close IMO.
and really what are we looking for in a gun oil? simple for me. proper operation of the firearm and rust control. and what we require for proper operation of a our firearms, depends upon what type of firearms we are using the products on. an AR run hot and heavy, will need a much more durable oil than say a bolt action or lever action hunting rifle. and some gun oils are going to better than others at keeping rust at bay. and their are oils or products that are primarily made for just that purpose, and maybe not so good at proper operation of the firearm. sometimes we are all looking for that magical gun oil that will do everything we want, and do all of them well. as a result, many products are simply a compromise, and may not do any one thing well.
sometimes, we may just need to take a step back and look at our own individual needs of our gun products and sue what works for our own specific needs. look at your environment, your firearms, and your own use of those firearms and use the products that work for your specific needs and not someone else's. just because Brand "A" works great for one person, and they swear by it, and it doesn't seem to work so great for you, doesn't mean that Brand "A" is a bad product, just that you may need something different and it works well for the other person given their conditions and needs of the product.
i use a variety of products. Rem-Oil, Lucas Gun Oil, Mobil 1, and others. all have their places in what i use them for. i also use a variety of different types of bore cleaners for the same reason. they all have their place. if someone asks me for ideas for a product, all i can do is suggest what i personally use, or products that i have used before. i would only give an honest assessment of the results i got using those products, and they may or may not be a great product for someone else.