RN-
I own both and the Sage is a little bigger and fits in my hand better than the Delica. The Sage is an awesome blade for the price, especially the Sage I. Here are some specs for comparison:
Delica:
length overall 7 1/8" (181 mm)
blade length 2 7/8" (73 mm)
length closed 4 1/4" (108 mm)
cutting edge 2 9/16" (65 mm)
weight 2.5 oz (71 g)

Sage:
length overall 7 1/8" (181 mm)
blade length 3" (76 mm)
length closed 4 3/16" (106 mm)
cutting edge 2 5/8" (67 mm)
weight 3.2oz (91g)

The difference isn't that big when comparing specs but the Sage just feels bigger than it is and is more comfortable to hold. You can't go wrong with the Sage or Sage II. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />