Highly recommended outlet which brought a HUGE difference in my system when compared to the standard switched wall outlet. When combined with Acrolink cords it is heaven.
IMHO your amp is already very good and a reasonable match for your current speakers. Since you have a dedicated room and have the space - why not consider a speaker upgrade or a sub first? (For the money I think this would give you the most bang for the buck...a sub for the low end or a bigger three way to give you more dynamics and low end)