so i am not one of the old-school players who bemoans the wireless smartgun as the end of shadowrun; i think there's a pretty defensible interpretation that the "lock-on" of the smartgun is helped by a combination of sensor fusion and environmental data in wireless mode, and the change from the dice pool bonus to the accuracy bonus is really more about a game-mechanical change than "suddenly old smartguns sux"; no, new smartguns is betters is all.
however, this does beg the question: why shouldn't a wireless smartgun benefit from sensor targeting rules? interpreting slightly creatively here, but if one could put a rating 3 sensor package into a targeting scope or similar package (don't see why not, effectively hand-held, has capacity) then why not use that for active targeting purposes? sure, you get the -3 to your perception + intuition test against metahumans, but you could run the sensor with wires into the smartgun hardware so there's no need to worry about wireless. a simple action could give your target up to a -3 defense penalty on top of rocking them with autofire. better yet, a wireless smartgun could let you paint targets with better sensors on connected drones or other separate devices on your person (like that nifty helmet on full body armor, say). seems like a win-win for corpsec; put high-quality sensors on your property or your guards and their guns, and your security is more likely to see intruders and more likely to hit them in the first place.