They are both excellent scanners. If the portability of a hand-held is not a requirement, I would choose the BC796D. It's display is much larger, with better illumination. The audio is stronger, and has a larger speaker. It is much more rugged, and will likely hold up better over time. The only drawback is during a power failure caused by storms, or blackouts, when you might want it most, it will be inoperable. For this I have a 12V GelCel, on a charge maintainer, which will run my radios for several days.
Some of the new features found in the BCD396T are impressive. But in real day-to-day use, I'm not sure if it makes that much difference. It depends on the individual. I do not require 6,000 frequencies, nor do I need, or even want the new "Tone Out" feature, but I understand why this would be great if I were a fire fighter. The dynamic memory is interesting, and may even make programming just a little easier, but up until now, I've lived just fine without it.
But hey, what do I know? I've gone from GRE's to Unidens, and back to GRE's in less than two months! I've had base/moble units, and I've had hand-helds, and now I have both! So buy one, or the other now, then buy the wife the other one later! :shock: