Originally Posted by
speshelite
There's no getting around the fact that a much larger surface area for the pad provides superior braking power.
The larger surface area does nothing for you. Friction force is dependent on the normal force and the coefficient of friction. By sticking with your original caliper and your same hands, you have not altered the normal force in any way. Your rims are presumably smooth yielding a consistent surface with which the brake pad will contact at any given time regardless of pad size so your coefficient of friction is not variable based on pad size. So the only way you are generating more braking power is by changing the coefficient of friction with your new pads. Your new pads would do that regardless of size, however, being larger does mean they'll last longer. But that's it. The standard road size pads in the same compound would give you the same braking power.
Originally Posted by
speshelite
I suspect that this single hack alone would narrow the gap between rim brakes and hydraulic disc brakes to zero in wet conditions.
This a massive assumption (and in my experience entirely not true) but even if it were, I'd still prefer discs because I would not be losing material off my rims every time I tried to slow down or stop.