FWIW, there's someone on AVSForums that lives in Oregon, where reception with Superdish is suppsedly not possible. He's using a Primestar dish for 105 (a la "poor man's Superdish"), and gets a solid 64 signal reading rain or shine. He says alignment was tricky, however ('not surprising).
This isn't supposed to be an issue until when/if Dish rolls out an HD channel that isn't already available on 110 or 61.5/148.
However, I want to add a 921 as a second receiver, which counts as three receivers total (2 tuners in 921). But I currently have a Dish 500 with a legacy Twin, and a Dish 300 with a legacy Dual for 61.5, going through a SW21.
If I got a Superdish with a DP34, I would just need to get the DP adapter for the 6000, and be done. But with the current 500/300 2-dish setup, I need to replace the Twin on the 500 with 2 Duals, and get a SW64. Not cheap. This new hardware would become obsolete when it became a requirement to move to 105 due to new programming only available there. An expensive waste to throw out the legacy equipment only recently purchased.