I would agree with what you've said and should clarify my earlier statements. The 925 is not altogether 'undetailed', but the other 2 players do look slightly more detailed and more natural. When you do a side by side comparison on the same TV and switching between the players at the same time, it's straight away obvious that some of the detail looks like it has been smoothed over on the 925 almost like DVNR. You only really notice this when you do a side by side comparison, otherwise if you are just watching a movie the 925 looks fine for the most part except for the crappy comb filtering especially on strong colours.
Yeah, the HQ should always be set off on the 925. It looks truly awful with that on.
I checked the circuit diagrams for the 4300D and the BNC connector comes from exactly the same place as the RCA connector. There won't be any difference in picture quality or detail if your DVD recorder or capture setup uses RCA plugs.