My thoughts on the initial topic. As far as group builds, I rarely do them for a couple reasons. First and foremost is time. I have enough builds I want to do plus the review items. I suppose if it coincided with the correct group build and the kit matched, I would do it.
I suppose second for me is topics. I build things that interest me so that might rule out some items. For me, P-51's, Spitfires, 109's hold no interest but, again, if the topic was good and matched I would be in also.
We could try one and see what rings out. Looking over the total posts for the last year, I see 3-4 people who build regularly (Mark, Gil and a few others) so I am not sure what the participation would be
Dave