Currently tracking the Grado Reference Sonata at 2.0g. Which is the maximum recommended by Grado. It now absolutely sounds like all the reviews said it would. Luckily I googled up a thread from the Steve Hoffman archives where someone was having similar Sonata troubles, namely a glaring midrange and occasionally peaky treble. They suggested cranking up the VTF. So I went from 1.5 to 1.8, and that made it better. So just for kicks I put it at 2.0. And the bass now goes crazy deep, and the midrange is finally lovely and liquid, without any of that nasty glare. I tweaked the alignment one more time using the Technics Baerwald Arc Protractor, and ran it through all the applicable tests on the Hi-Fi News Test LP, and it seems to be performing marvelously.
Based on my experience with Platinum Statement, and also per GE's recommendation, I'd hypothesize that best way to go with a Sonata would be to get the low output Statement version and pair it with a powerful and dead quiet (solid state?) soundstage. I would love to hear a Sonata Statement with say a battery powered unit like the Sutherland Ph3D.