Well for most it is a matter of being able to cool the car down between rounds. With an electric pump and fan it is easier to cool the car off than with a mechanical set up. AS for street driving I have never done it but know of a few that do with no issues. As for the pumps themselves I prefer the Meziere ones.

I run an alternator as well. I need the current to keep everything running on the car. There is a fair amount of electronic stuff on my heap.