Tank looks good - but I think it would look better with some wood! Of course that's a personal choice thing!
Also, I know I am late to the party - but I had RH's before that were easily 7+". Maybe closer to 8 or 9 - but I understand that could be the exception, rather than the rule. They were mature fish when I go them and then I had them for years - so they very well could have been 10 or more years old by the time I moved on from them.