Guys,
For those of who are interested I pulled my 3 year old Death Adder (DA) off the rack and shot it side by side with the Vyperkahn with carbon longbow limbs (VKL) tonight.
At 56# with a 500 grain arrow the DA was much quiter and barely made a noise. With the same arrow at 50# the VKL was definitely louder than the DA but quiter than the VK with the Hycurve limbs (VKH). For reference the VKH is quiter than a 10 year old Bighorn recurve I still shoot occasionally.
The DA had more hand shock than the VKL which has no noticeable hand shock.
At 50# with a 500 grain arrow the VKL was 2 to 3 FPS faster than the DA at 56#. Using the 1# of bow weight = 1.5 FPS rule which I've found to be reliable a 50# VKL would be 11 - 12 FPS faster than a 50# DA. I do know the Chris improved the speed of the DA about 4 to 5 FPS since I bought mine so the VKL is probably 7 - 8 FPS faster than his current DA with glass. This is in line with what he told me a few months ago when he finished my VKL.
So to sum it up the DA is quiter while the VKL is smoother to draw and shoot with less handshock and much faster.