My latest discovery for better neck shaving is that I need aggressive razor i.e 39C or R41 with a sharp blade, currently am using Gillette Silver Blue. I will do a NW-SE pass on both sides of my neck i.e. non-symmetrical. This pass I have found to be closest to XTG I have found on my neck. I do short strokes, almost buffing. Two of these passes and I have irritation free DFS result. Not yet perfect BBS but the best result I have managed to get consistently so far.
ATG passes seem to drive the blade into skin and WTG passes don't cut enough. I tried five consequential WTG passes and the result was as good as with one WTG pass with much more irritation.
Summary:
-Aggressive razor, sharp blade
-Two identical XTG passes, no WTG nor ATG passes
Your comment on doing a NW-SE pass on both sides of the neck caught my attention right away. In my own quest to master shaving my neck I
find myself doing the NW-SE XTG pass and I use short strokes as you describe. This seems to the best way of dealing with my neck that I have found so far.
I also concur with your observation that ATG passes seem to drive the blade into skin and WTG passes don't cut enough.
Thank you for your interesting and helpful post!