Hi Emil, I have a 3.5 year old Darbee Darblet DVP-5000 for my 50" Panny ST-60 plamsa (the last year of manufacturing plasmas) with DirecTv and I love mine big time. I'm using simple Monoprice gold plated HDMI cables. When I first got it, I could only use 40-60 (out of 120) processing in Green Mode before artifacts showed up. But then I shitcanned the cheap AC/DC 5 vdc 1A wallwart power supply with a Meanwell medical grade 5 vdc 5A desktop SMPS for just $24 and now I'm up to 95 processing for a crisp clean picture w/p artifacts.
I hear the 5000s is even a better processor, I'd pounce if I were you. I'd also add that I had my Panny ISF -calibrated before adding the Darbee Darblet. I highly recommended thing to do.