As far as using 3rd party solutions: I see your point, and actually used to administer homespun "code challenges". The downside with that approach is that it adds a ton of overhead. As terrible as it may seem, we may not be able to invest that kind of time unless we're willing to be more heavy-handed in candidate selection early on. In at least one case, there was a candidate who had a fairly unremarkable resume but really impressed us in the interview process, and they may have been eliminated earlier on if we were more selective from the beginning.
Personally, I completely refuse to do any form of live / timed coding test but might accept a homework assignment with a very generous deadline if I feel it's well aligned with something I'm willing to spend personal time on, assuming that they're not satisfied with what I already have up on GitHub (although I'd expect a good explanation for why that's the case). Otherwise, I'm more than happy to discuss past projects, system architecture, API design, development practices and so on.
In the same time I can watch your BS infomercial or read your CEO's book on how the company is a ship or whatever, I could sent off 5 different applications to companies that don't waste my time... guess which wins