1) #8 The solid-shaded, two-colour apple seems appealing visually than an outline-only apple. A refinement of the original #1 'outline' would be quite interesting.
2) #1, #8 The new stalk used in #8 looks good to but the actual fruit shape in both #1 and #8 is not apple-like enough. It seems slightly top-heavy and resembles a heart. Keeping the stalk attached and using an outline should be distinguishing enough, but more in line with the proportions used in other apple logos like
http://www.google.com.au/search?q=apple+logo with a thicker base.
3) #8 The green plus symbol doesn't strike me as very medical and making it red, ie a red cross, wouldn't work as there is already tight ownership over the red version. I'd like to see the plus symbol replaced with something else.