I'm at 6 of 17, so closer to the grass rather to the roof and it should matters!
it's all about that seeing ... well, I would prefer a nice lawn to my narrow balcony with a limited firing sector, as the sun only appears now from 09:20.
I've no measurement of the given Quark, but it's with 2 non-uniform areas at sides of FOV, I think as usual.
I had also experience at the mountain observatory at about 2000m altitude in October last year. I imaged the sun with C11 from the 6m tower under clear skies, but finally the seenig was worse then last Saturday. Although I was surprised with SSM figures (calibration?), today SSM varied from 0,8 to 4 and pictures not of the same level.
BTW I am not the only one here in Moscow was imaging the sun last weekend with C11, at least with not the worst result.
regards
Leo