Currently using a Oppo 980h and just picked up a Pioneer VSX-01txh which has a Faroudja DCDI. Was completely happy with how the Oppo did the upconversion to 1080p but wanted to free up a hdmi port. Using component and output the Oppo at 480i for the AVR to deinterlace to 1080p.
While ago I had a Samsung DVD player with a Faroudja DCDI and remember hating the macroblocking it introduced, alot of patchy solid colors reminding me of a low quality video on youtube.

My favorite movie to check the macroblocking is "Vanilla Sky" at the birthday party scene, Tom Cruise's red sweater looks just blotchy. Surprisingly now this is barely noticeable. The DCDI in the AVR passed all HQV tests with flying colors, only downside is the picture is slightly softer than the Oppo output at 1080p. I believe Faroudja was always bit softer and film like.

My Denon 1909 AVR also uses Faroudja FLi2310 processing. I have a 50" Samsung, which in it's official thread many complained of macroblocking from Faroudja processors. I never got any from the Denon. I agree ith your conclusion to it's processing. It has a very nice, clean picture, just a little soft. I ended up getting a DVDO Edge external processor. The Edge was SLIGHTLY cleaner, but a little sharper. I was impressed how good the Faroudja looked from my AVR compared to a very highly regarded $600 external processor.