Problems with homemade discs really doesn't having any bearing on the quality of the player- it's not evidence of getting a bad unit. Burned DVDs are simply not all that compatible, and if you have much experience with them you'll find that there's a lot of issues relating to compatibility between burners/media/players. You may burn Brand A discs in a Brand X burner and find they'll play on all your machines. But switching discs on the same burner, or even burning Brand A discs on a different burner, may result in a DVD that won't play on that same machine.
I've tried 8 brands of DVD-R/+Rs, burned on 3 different burners, played back on 11 different stand-alone machines, and the results will curl your hair! The recordable spec is almost pure anarchy, and there's almost no way to tell what will work until you try them.
FYI, the player that would play the highest percentage of discs is my cheapo Pioneer DV-260S that I use in my b-room system. This will flawlessly play discs that my Pioneer DV-45A won't recognize, and will get thru some discs my Denon won't play. Also, in case anyone cares, Prodisc DVD-Rs burned on a Pioneer burner work 100% flawlessly in my DVD-2200. I use the inkjet printable ones...