I think DAM and DID are awesome and are on par with each other but DID is doing more WW2 era things. So hard to compare.
E&S is great but the quality can be crap on smaller items (buckles, straps, which are very minor nitpicks depending on the person) but their molds on weapons is near equal to DAM. Also, E&S releases always have the IRL gear on their figures, so I find that interesting. E&S quality has been gradually elevating their quality and it's been showing in their releases. Also, when mentioning E&S, you have to include their sibling company general armory. They are one in the same.