Thanks for all the feedback. I have done a lot of research in last few week, including reading Ron Shimek and J. Sprung texts I have. My conclusion is DSB provides the greater biodiversity and ecosystem I'm looking for, in don't think I'll be able to decline these benefits. I also have come to believe the nitrification capacity of the DSB will double the capacity of LR in system.
But going DSB requires maintenance due to 1) some same replentishmetn due to gradual arragonite sand dissolving; and 2) detrivore/infauna replacement here and there (kits form InlandAquatics.com for example).
Further, as I build my LR aquascape, I'll make sure the LR bears on base rock or PVC or fiberglass rod foundation, so as to avoid gradual dissolve of aquascape bearing on dissolving sand. Anyway, this is what I've learned. Always intersted in folks experience on this major decision in my build.