The movie Gettysburg gives a very good representation of what happened at Picketts charge. You might enjoy seeing it now that you have been there. Several years ago I walked Picketts charge. Looking across the field you dont understand how undulating the field is, until you walk it. Then when you get to the roadway, there were the fences to deal with. It made the Confederates easy targets.
Little Roundtop is one of my favorite places to go and contemplate. There is nothing like sitting there mid week when there are few visitors.
My only dislikes of the new visitors center is the fact that the handicapped parking is a quarter mile away, at the bottom of a hill, and that you can't split up the tickets and say go to just the museum and not the museum, film and cyclorama. When you've seen the cyclorama 4 or 5 times, you might like to skip it and just go to the museum.
Glad that you had a good time in my "other" hometown.