Mattnshilp, love your system, especially the Esoteric gear and computer transport. That Rowland preamp looks stunning! If it sounds half as good as it looks you got a winner.
In terms of room treatments, I would also lean towards the latter and go simple. I am sure a full Rives design would be great but for the cost I think you can get some great improvements going the route of premade treatments. I recently added bass traps and was floored by the improvements. I am slowly adding more. My next move will be to treat the 1st reflection points. Needless to say I am very happy with the improvement I heard.
Good luck and looking forward to seeing what you do.