I have two Texas Blues necks (asymmetrical .86") and two C shapes (.83" and .85") from USACG. I'm a huge fan of the asymmetrical contour. On my third neck I finally found exactly what I wanted, .86" asymmetrical with 6150 frets. I actually am about replace the first neck I every bought (C shape .85") and am planning on buying my third asymmetrical.

I don't feel the spine at all, in fact you would have to look pretty closely to even tell they are asymmetrical, it is very subtle, but your hand notices. I find it very very comfortable, fast - perfect. My style I only use my thumb to mute the 6th string, I almost never fret it, so the fatter top part of the neck just looks good and is and hand full, yet I have no problem reaching my fingers under. Really nice necks.

BTW - I find my two asymmetrical necks definitely feel thinner than the .85" C shape. Also the one with the 10" radius feels slightly thinner than the one with the 12" radius, so I guess all that plays a part. (BTW all C shapes are 12" radius).