I'm looking to upgrade my QS2002 733. I am comparing single vs dual-- Prob been asked many times before, but Is the 1.4 faster than the original QS dual 800? i think i could get a dual 800 from ebay for maybe $225 or so, compared to the $300 or so for the 1.4 single. And can I use the 133 MDD dual 1K in a QS?