I'm good on form. Very controlled . On barbell's I use the smith so I can go heavy without stressing crushing my throat. I don't cheat at all . If I can't get the rep I can't get it. I do alternate rep speed every 8 weeks . I'll go speed and drop weights . De-load weeks are good for old men!
You are NOT good on form if you are worried about crushing your neck on bench. Go to Youtube and watch Dave Tate's videos on bench pressing. I guarantee you it is a form issue.
After you watch the videos, switch to the normal bench. As far as I'm concerned, the Smith machine is an injury creating device. There is no exercise for which it provides the proper range of motion.
Remember, feet back towards your body and solid flat on the floor, back properly arched and flexed, butt on the bench, shoulder blades together and on the bench, lats flexed, bar stabilized after lifting off the rack, tuck your elbows in as you lower to your lower chest, tight grip, imagine you're pulling the bar down to your chest with your lats, reverse the movement, repeat.