So I'm thinking about throwing 16 lb equipment for the summer and I was comparing core numbers on a few different balls and found that the RG drops and the Diff goes up when comparing a 16lb hy road (RG 2.52/Diff 0.058) to a 15lb hy road (RG 2.57/Diff 0.046). Just by the difference in numbers I'm assuming if drilled the same and thrown the same the 16lb will roll a little earlier and have more track flare due to the core numbers. So I'm wondering  will I still get that great hy road reaction/shape that I've seen out of the 15lb hy road in the past?

The Hy-road balls are some of the very few balls that have a significant difference in specs between weights.  I think most will agree 15lb balls have a significant advantage over 14lb due to how it goes through the pins without much deflection.  There honestly is not much difference from 15lb to 16lb though.  Its really a matter of personal preference.  Most of us throw 15lb simply because we can throw it harder and faster.

Understood... But what difference do you think there will be in the reaction since the Diff is so much higher on the 16lb core compared to the 15lb core. I mean I know there will be more track flare due to the increased Diff, but it seems the increase in track flare would make the 16lb version a monster on the backend.

I have a 16# Hy-Road and T-Road Solid. They do roll and flare considerably more than the 15# models. Also, the 16s hold the line well going through the rack... little to no deflection.