well mine is very small, ultra comfortable. Small C shape, not as chunky as my ASS'es, the Luke is comparable, but it has the V neck which feels a tad bigger than the silo special. my 20th Silo has a similar neck to the Silo special. the best necks i reckon.
my mate Dave has a 2000 Silo special with a CHUNKY neck, so i dont know whats goin on there. but all the ones ive played over the past few years have had the same small neck like mine.
The one and only Silo Spec I've had the pleasure of trying out was there at Make'n Music. Great store. The Silo Spec had the HSS configuration. I believe it was Vintage Sunburst.
silo special neck rules, its my main guitar, they are thinner than my axis necks, rob described it best, shallow c shape, very comfy, youll love - it go for it -