I agree with JC that just the rear saddlebag guard (without) rails wrapping the bags does not detract from the lines of the bike's paint scheme.
When the SEEG's came out in '04 & '05 they had no protection at all for the bags, just like the 2010 SESG's. In '06 with the SEUC the full guard was standard which will protect the bags if the bike his tipped over. Having said that, I don't know if it would do much for the stretched bags?

On the choice of black or chrome - On a dark painted bike the black guard does look really good and is hidden to some extent. My only concern is where do you stop with the black scheme? Once you've done the guard you may want to continue with replacing a lot more chrome with black parts.
On another thread on this site there is an awesome looking Spiced Rum SESG with most of the chrome replaced. It really changes the look of the bike, but it does cost to make those changes, but then again it could end up being a work in progress over the next couple of years.
For many the installation of the full rear guard provides "peace of mind" and therefore well worth the money.
Enjoy your new ride.