I have a Henry Golden Boy in .22wmr. I love this rifle. The action is smooth and it shoots very well. The Big Boy has a brass reciever (as you likely know) but the golden boy has a brass plated aluminum cover over the cast metal reciever. This has not been a problem and it always stays shiny whereas the Big Boy will need polishing if you want the brass to look bright.
As far as how the big boy shoots, I have only heard good things but have not had an opportunity to try one.
Look on the Lever Gun forum, you will find lots of info