I have the BDP-103 and love it. I got it for the video processing power it has and am very happy with the PQ it produces. That said, I've been looking at getting the Darblet but am not sure if I will see any PQ benefit given the abilities of the 103 that are currently enabled. Do any of you 103 owners also use the Darblet? If so, do you recommend it?
What the Darblet does is very different than any of the features in the 103. The 103 has traditional edge sharpening and contrast boosting options. You should turn those off. The Darblet uses proprietary technology to enhance detail without artifacts. The two products are complimentary.
There's a lengthy thread about the Darblet in the Video Processors forum with more information on what it does.