I did run a geared starter for awhile, eventually I broke the starter gear due to having the wrong ring gear tooth count on my flywheel. I also went through a couple of OEM starters before I figured that out.
My point though is this: The geared starter did indeed crank more slowly than the OEM starter. This was problematic under some hot start conditions, the motor would crank for quite awhile before it fired up. Like getting gas, buying a drink, hanging around "just long enough" to get the engine good and heat soaked but not long enough for anything to cool down. Under those conditions I still have to crank the motor longer to start, but it spins faster with the OEM and catches much sooner now.