Well, I can't answer that, but for me it's a matter of reviewing all the published material, but more importatntly hearing from real users and then listening for myself. That takes a little time for me, anyway.
I don't put much stock in published reviews; had way too many instances where my own personal experience in how something sounded was not in agreement with somebody getting paid to say something. I do still read them, though. I have no doubt the SP1000 is a potentially great universal, but I place more weight into what people like you, and other owners, have to say as a guide in my own process of narrowing down the field. The one thing that is holding my actions at bay is a report from one or more well regarded AgoNers on a direct comparison between the SP1000 and the Marantz DV9500, primarily from an audio POV. I already know they are both great for video. I'm already an owner of a DV8400. It's a nice sounding player, but it does have the characteristic Marantz sound. I hear the 9500 is less so in that regard, but by comparison to that I'm not sure how the SP1000 sounds. I know that A+B does not necessarily = C, but I am frustrated with the lack of user experience with direct listening to both of these newer units.
I suppose I could just buy both and return the one I don't prefer, but I don't know that I could get them fully broken in for a fair comparison.