I haven't heard the v4 Studios - like you, I used to own Studio60v2 (mine are actually about to relocate to Oregon soon, actually), but I haven't had a chance to listen to the newer generations of those speakers. The 990 will likely have an impact compared to your Yamaha, so that's probably the first place to start in getting the sound where you want it. I'm going to make a sweeping generalization for a moment, so forgive me, but the 990 may be more neutral than your Yamaha if my recollection of Yamaha receivers is accurate. That may take some of the brightness away, without sacrificing detail or clarify.