Ha 300. IMO the advantages of a 30 mm are:
1, Stronger tube(because it is bigger around)
2. Can be set up with more elevation and windage adjustment. Notice I say can be, because some are not.
3. Will allow more light transmission through the scope. You have to have the quality of lenses and coatings to take advantage of the larger tube size.
4. Some of the 30 mm tubes allow the Parallax to be adjusted with an additional turret knob in the center of the scope. This is more convenient, has less working parts, and balances the weight of the scope.

My choice would depend on the use of the rifle. For strictly deer hunting I would choose the stadard scope without the AO. In a deer hunting situation the AO has no use.To take advantage of the 30 mm tube I would go with a slightly larger objective diameter, like a 50. I would not go with the fifty in a one inch tube. Tom.