The advantage of the 1.6 ratio rocker would be that the cam lobe can remain less aggresive, thus the remainder of the valvetrain taking a bit less beating.

Simply put, to get the higher lift on lobe design alone it will have to rely on steeper ramps. When you start looking at that whole "area under the curve" mapping I would suspect that a higher lift lobe would have less resulting area (at the valve) than the lobe meant for the lower lift. After all, the only way for it to match the higher lift would be to make up the mechanical ratio advantage of the 1.6 rocker by building in more area at lobe, which would presumably increase cam duration, etc. etc...end result being you are no longer talking the same cam specs...again, all of this if very general though!

Just what I have learned over the years...my current W2 build made we go from MP 1.5 rocker to Hardland Sharp 1.6 pieces.

In my current ride (360 motor, heavily ported 596 castings) I did go from 1.5 to 1.6 on a Hughes HE3844AL hydraulic flat tappet cam (.536/.540 lift @ 1.5, and .571/.576 lift @ 1.6). Not a big cam by any means, but this is a street vehicle, so plenty enough. The butt-meter told me the motor felt more responsive, the idle sound certainly changed, it had more "crisp" to it...