I got two from DISH because my 6.3's would not support the HDTV that I needed them for. Well they work great with the TV and horrible with my 722. After talking to DISH they confirmed that the 21.0 won't work well with the 722 (not k) and gave me my money back and told me to keep the remotes. And the two that I have you really have to mash down on the buttons to get them to work. The last tech through here noticed this and mentioned that he liked the 6.4 better when they can be used.
Will trade for two new 6.4's, the best remotes I have encountered to date.[/QUOTE
Strange--I have 4 21.0s for my 622 & 722 and they work flawlessly for the receivers/TVs. Much better than the originals. JMHO
Ed