I think the post-metro suburb green islands are really interesting. Gaithersburg and North Bethesda have a lot of big town center style development that make it a lot easier to walk/bike to shopping, have a mix of office and retail on-site, and also have bigger green spaces. But Reston doesn't have that (I don't know how comperable rtc is, I've never been there). And leisure world/Northern silver spring don't have that modern development style. I think the Gaithersburg green island is probably a mix of modern development styles and the working-middle class population.