Hey ksubs, the nerf was necessarily to the extended mags - it was a sweeping change to a lot of the weapon mod systems. Now there are plenty of mods with only positive traits available, as well as some mods with stronger positives, but slight negative trade offs. There's a mod now that is more in line with what you're looking for, adding +20 rounds with a -10% reload speed.
This change allows for optimization in certain aspects, but enables players to have generally improved weapons in all facets if they don't want to work around the negative traits.