I am a long time SD customer in good standing and have the following units. Two older 4xx receivers a 3xx receiver and two 505 units. From what I have been reading here, upgrades may soon be inevitable. Should I wait until such time as we are forced to upgrade or should I look into this now? I wouldn't mind upgrading my 505's to a 605 & a 630. My other 3 receivers can stay SD but they could also go HD if the deal was right. Would you wait or would you call SD and see what kind of deal I could get?