I have a Pioneer 420 and 5100.
My previous HDD/DVDR combo was a panasonic.
Despite comments on this forum that the Panny offers better quality I have not noticed.
Unfortunately what Phelings does not mention is that is Panasonic HDD/DVDR combi was a Panasonic HS2 - a 2002 DVD recorder - since then Panasonic models have upgraded the MPEG encoding
two times. The encoder abilities of the Pioneer range are actually very similar to the HS2 though: the duration they can record at full resolution, for example, is the same on both models.
Current Panasonic recorders (E55, E65, E75, E85, E95, E500) are noticeably superior to the Pioneer's: marginally so between 1hr-2hr, noticeable so between 2hrs and 2hrs 20mins and significantly better at recording lengths over 2hrs 20mins.