In the ranges a handgun encouter are usually at, it isn't significant in any measure (velocity loss) IMO. We're talking miliseconds at 30 feet or less from muzzle to impact. If you are THAT worried about it ten go with lighter bullets to offset the variance.
I wouldn't obcess over this facet of SD, personally. I carry 147gr in 9mm for the same reason. A lot of people write about the 124gr being faster and all, but seriously, when engaging a target at 30 feet or less it really IS insignificant. Just sayin'.