User blog comment:Willbachbakal/Singleplayer Weapons/@comment-3195894-20110103093042/@comment-1330314-20110104093227

Basically, if you only take basic upgrades for your weapons, you might have a much harder time fighting Splicers. There's no straight damage upgrade to any weapon, so you'll need the power boost final weapon upgrades give so as to be able to cope. It's also a question of enjoyment: if you take all three basic upgrades for your weapon and stick with it, you might end up ignoring it completely afterwards just because it won't be powerful enough to deal with the rising difficulty.

This is merely a quirk of my system, though. It's perfectly possible to create your own upgrade wheel system and have the player be able to choose only basic upgrades, as long as the advanced upgrades remain on the same general power level as the basic ones.