OK, I'll bite.
As you may know, HoustonGuy, I also have both the Panasonic E80 and Pioneer 420 recorders (not the XP-30, though). I also have a great deal of respect for you, your desire to communicate your enthusiasm for your purchases, and your experiences with DVD recording and pre-digital recording as well. I have regarded you as a sort of older brother in all this DVD recorder stuff. Still, I don't think of the Panasonic-vs.-Pioneer comparison (or Panasonic-vs.-Anyone-Else comparison) as a contest, and certainly don't see it in the stark black-and-white relief that you do.
However, those considering a hard drive DVD recorder for editing, even in the future, might benefit from some information about past and current models, and how their users like(d) them.
For those wishing a comparison of the editing features of these recorders based on a non-HoustonGuy opinion...
1) the Panasonic editing screen is much bigger than the Pioneer. In this sense, the Panasonic is easier on the eyes.
2) While in editing mode, the Pioneer's editing interface allows the user to skip to previously-placed chapter markers (as does the Panasonic). Unlike the Panasonic, the Pioneer also allows the use of TIME SEARCHING while in editing mode
. This allows skipping to a particular minute in the recording. The Panny's version of TIME SEARCH, TIME SLIP, is not available in editing modes. To me, this has always been the most inconvenient aspect of the Panny E80 editing interface. To divide a two-hour recording into two one-hour recordings is much simpler if skipping ahead exactly 60 minutes is enabled. On the Panasonic E80, if one is in the editing modes (shorten segment or divide), to skip to the place where an edit is desired one can fast-forward scan (risking an overshot of the desired division), press commercial skip several times, or rely on markers placed while in the viewing mode. These are all also available on the Pioneer, but so is TIME SEARCH.
ABOVE WAS EDITED TO CORRECT FOR ERROR. COMMERCIAL/CM SKIP does operate in both the E80 and 420 when in editing modes. Sorry, but my memory was faulty. Maybe I'll get an upgrade.
3) The Pioneer 420 allows high-speed copying of edited material to DVD (using "copy lists") without actually altering the original recording on the hard drive. To create a DVD of edited material on the Pan. E80, one must either (a) edit the actual hard drive recording and do a high-speed copy or (b) create a playlist from the hard drive recording and do a lossy real-time copy to DVD. (a) risks making an mistake that permanently damages the recording (to say nothing of fragmenting the hard disk drive), while (b) both takes longer and produces inferior visual results.
Since the E100, (and with models including the E85, and E95), Panasonic has incorporated high-speed playlist dubbing features that are similar to those of the Pioneer 510/420/520, so the disadvantages of the E80 with regards to item 3) are mitigated in more recent Panasonic offerings, if not entirely moot.
As one person (in addition to HoustonGuy) who owns both the E80 and 420, I give the editing match to the Pioneer 420 on points. Sorry HG, but this bout is gonna have to be a split decision (assuming a "winner" can even be declared).