The position on most mapping software updates about once per second. It does so from the most recent NMEA location statement. Each statement is about 70 bytes long, which at 4800 baud take 15 milliseconds to transmit. So, increasing the baud rate won't speed up the update rate of the software. It may even be that the GPS unit still transmits the same number of updates. It is just that at a faster baud rate the statement takes less than 15 milliseconds to transmit. There are other NMEA statements that update the satellite information, signal strength, etc, so not every statement is a positional statement, but I suspect that most GPS units work through a sequence of statements at a measured pace that is independent of the baud rate. From observation of my statements coming in, there don't seem to be more arriving every second at a faster baud, they just each arrive faster with more time between them.
So, IMHO, there is no reason to increase the baud rate at all, unless your software is capable of updating at a rate faster than once every 15 milliseconds.
But, like Tim the Toolman, some people just want to be faster, even if it isn't really better.
