Well, I remember I was reading this article. People who bench on smith machines had 16% less strength then free weight benchers. Funny enough this was the opposite for people who squat since the smith machine isolates the quads.
Anyways, it depends on how you feel. I’m personally doing dumbbell benches and smith machine bench because I have a major weakness in my left pec. Using the smith machine without worrying, I can make sure I’m using my left pec as much as possible all the while with the dumbbell bench I’m fixing the problem.
If you’ve been training a hell of a lot longer then me, you should move to free weight bench. That’s where the real stuff is at. I’m just not ready to go free weight bench yet. I have a lot of lagging muscles on my left side to fix.
So it’s all really based upon how you feel and what you want. There’s nothing wrong with smith benching even if you don’t have lagging muscles but the point of free weight benching is there’ll always be that extra sway in that movement or a difference in how you push the weight up and down that’s where the extra strength kicks in and the effectiveness.
Whereas the smith is one straight up and down controlled movement.
Also, I think if your technique on the free weight bench is bad, Smith, I think, is a decent way to fix it.