I was also there Friday night for the first time, so interesting to see this.
I have to say that I share your thoughts about the breakfast, which was excellent. I thought check-in was fairly lackluster, not particularly friendly - although to be fair I would have expected there to be more staff available to deal with the numbers checking in.
Agree with the water pressure - it's not awful but a more modern property would be better. My room - standard king with no upgrade available - was in good condition but the property does reek of the Reagan area and some of the common areas could do with updating.
I drove to the property so can't comment on the shuttle. For the price I paid, I was happy - though I'm slightly surprised that you thought that it was nicer than the main airport Hilton, where I haven't stayed but didn't think that this hotel was a stand-out in terms of quality.