As you alluded to, there are many factors that go into a purchase decision, quality being one of them.  Looking back to VHS vs Beta, clearly the lower quality format won.  The consensus appears to be for the following reasons: lower cost, more options on devices (Sony vs the world), more content (once they figured out that playback of pre-recorded content was the killer app rather than recording TV).  In the case of SACD and DVDA, there hasn't been much uptake.  Issues that I have noted are competing formats with no clear winner and cost.  From what I have read many people beleive the quality gain for the additional cost isn't sufficient (players and content). 

And then we come to HD-DVD & Blu-Ray.  From what I have seen, the quality difference between the two isn't insignificant (as well as the features) to the general public.  Learning their lesson from beta, Sony has managed to line up quite a few allies, but so has HD-DVD (Toshiba). Their looks to be a slight cost advantage to HD-DVD (at least initially).  Then their is the problem of content protection potentially being turned on rendering older sets w/o HDCP via HDMI-DVI support out of luck.  So how do you choose?  Most articles I have read are recommending don't buy.  I agree with that since this mess is a result of greed and an unwillingness to compromise. Net result: everyone loses.  In the mean time, try a good upconverting DVD player (see Ben's Blog) which can reduce the quality difference quite a bit.  Or, as the CE industry continues to squabble, look for HD content to be delivered online bypassing the whole format/player issue (and the CE manufacturers).