Inlet manifold gaskets

Thanks for all the good info.
I don't have an egr valve and yes I believe that the heads were for trucks. I picked up these heads new, a couple of years ago believing that they would be good for my build with small closed chambers. I am now only just finishing my build. I had a fel-pro gasket set which had the .015" thin metal gaskets but have seen on a few posts re builds that the metal ones aren't favoured. Is there any particular reason why members don't favour metal shim gaskets?
Thanks