I'd mention that one of the first companies to start producing commercial sites for national brands with Radiant was Digital Pulp in NY, way back in 2008. The fact that the early adopters were talented designers who needed to launch beautiful sites quickly speaks volumes about how easy it is to implement a template in Radiant. It's really great for marketing communications projects. I would consider Radiant to be better-suited for end-users with some design/development skills.
There's a podcast (http://radiantcms.org/podcast/) from way back in 2008 with the guys from Digital Pulp. It'd be interesting to give them a shout and see what they're up to today.
