Can't say anything about Superdeck. As for DWF, I've used it on PT wood but never used it on cedar. That doesnt' mean it's not a good brand for cedar. It just means I can't attest to its performance on cedar.
Olympic makes a good semi-transparent stain for cedar. If I'm not mistaken, it has UV and mildew inhibitors in it. Depending on exposure to sun, moisture content, humidity, and so on, that will dictate how often you need to stain. I'd use an oil-based stain, not a latex one. The latex one's don't bring out the grain as well as the oil stains do.
The stains that stand out don't really do that much better in terms of how long they 'preserve' the cedar between coatings. Mother Nature does that. So, if you go 3 years between restainings, that's good. I steer clear of stains that last only 1-2 years, like Thompson's. The 3+ year stains are ones like Olympic and Cuprinol. DO check the can for UV and mildew protectants. And do be careful with the pressure washer. Do use the kind of pressure that will cause delamination of the wood fibers. (That's the 'fuzz' you see when the siding's top layer is turned to a 'pulp-like' / fibrous consistancy.)
I got your e-mail. This should help w/that too. My best to ya and hope this helps.