In my case at least the aic7xxx driver takes a long time to register the SCSI disks on my system, so it certainly would not be faster.
This doesn't worry me as I hardly ever re-boot. Also there may well be some way to speed up this registration.
If you are talking about the SCSI bus reset delay time, you can certainly shorten that - at least for some drivers like the aic7xxx - by rebuilding the driver module. The reset delay time has always defaulted to 15000 millisec but I always shorten it to 5000 millisec.
--- Rod