I thoughoughly enjoyed the one day tour with Adrian. I'd recommend that, unless you're a WWII buff (which I am, but which the rest of my family was not), you consider just doing a  six hour tour of Omaha Beach and the private field in the vicinity where  a substantial German gun battery was excavated, and then end with the US cemetery at Coleville.  You can see Utah beach at a distance but you'll gain very little by going there. Adrian is a super-dedicated and passionate guide and could easily spend 12 hour days on his tours...but that will involve getting caught up in the weeds.  I would recommend Adrian to my friends, but would recommend that they have him stick to generalities and the big picture.