Fine... I'll answer my own question. LOL.
Blu Ray: I've got a modest setup. Still using a 720p LCD projector. Settled on using the Darbee (for now) at HD-60% setting. Full-pop is cool, but for Blu-ray, I prefer the more blended effect that HD gives.
All I can say is "wow"!!! This $260 device just added a few more years to my Panny PT-AX200's lifespan. (Wife very happy with that.)
Watched Sherlock Holmes: A Game of Shadows, Star Trek, and HTTYD. In all cases the image just jumps out at you with increased depth and detail. (Wonder how the actors feel about their wrinkles getting the Darbee treatment.) The Darbee makes my aging $1000 projector look like a $10,000 projector (or what I'd hope such a projector would look like if I could ever afford one.)
DVD: Used Full-pop for DVD, also at 60%. Watched parts of LOTR: The Return of the King, The Big Red One, and the DVD version of HTTYD - decently mastered DVDs.
The effect is much more subtle with DVD than Blu-ray. Still, considering the limitations of the source material, the Darbee definitely improved the image, especially at the foreground level. I'm using an Oppo DV-981-HD (again, older technology) and blowing the image up to 180" diagonal at 2.35:1 against a satin-painted wall. Gives a nice level of enhancement to the image, but certainly lacking the dramatic "wow" factor of Blu-ray. Nonetheless, I'm very happy with the improvement.
Anyone with a similar "po-boy" setup like mine should definitely consider the Darbee.
One question to the Darbee folks: Is unplugging the Darblet between uses recommended? I noticed the device remains a bit warm when plugged in. Want to maximize its lifespan.