I use the US GOES ('Global Entry' facility NEXUS) and find the DUB USBPA pre-clearance at Dublin to be a very convenient service. Instead of waiting in a long, time consuming line-up at a US gateway airport, then having to get to the domestic terminal, praying your bags have made it also and worrying about them the rest of the journey, I am in the area I need to be to make that connection. Remember, your bags will not be boarded until you are confirmed admitted to the USA. And your description of the acceptance and admittance by emigration procedure, at the gateway airport, as being a "doddle" does seem a little fanciful, in my experience. It isn't even a "doddle" using NEXUS facility on land crossing where there is a separate vehicle lane and entry booth.
PS: The one-offs travelling on ABC's won't likely care about pre-clearance, not having, for the most part, to concern themselves with on-ward connections.