I like the dry and Herman Gulch areas better, but you have a little less elevation to gain by going in from the tunnel. Also, I don't know if anyone ever saw any billies around the tunnel. Just nannies and kids.
Jones Pass is of course easy to access, but I never saw anything there, though I know goats get killed there. Vazquez Peak, Iron Creek and some of that country is pretty tough to get to. You can glass the Herman and Dry Gulches from a pullout on Loveland Pass if you have decent optics.