The coverage in the US has been appalling. Because of the time difference, NBC are trying to hold onto the results etc. live, and present it all in the evening more or less "As if" it were live. Just like anyone else, they predominantly show the events where they have gold interest, which means that until the track medals started to come all the coverage was pretty much swimming and girl's athletics.
I have been keeping up live on BBC iplayer, and the service has been absolutely outstanding both live and with all the catch-up utility on the site. In fact, Britain has handled these games with excellence in every department IMO.