By the numbers I see a difference as 1/16" what me think is insignificant. Really, why is that second type better ?
the smaller bolts most of the time break before the clamp tightens to the inner monopole, the bolt just shears off. Its pretty easy to break the bolt off even with a small wrench. The 1/2" nut size bolts must be 5/16" i think, you have to try pretty hard to shear that bolt, that and the clamp actually works, the entire monopole is just stronger all around compared to the older type.
Somehow we ended up with some this last summer and all of a sudden i got 4 service calls out of no where, they were all broken bolts after a storm went through. Before that i maybe had 1 or 2 service calls every 3 months or so that i couldnt fix over the phone.