Hi precision system.
I often switch from Swinging to Hitting as I cannot clearly see wich one is the best for me! Both are working well and distances are close.
Each going back and forth between the procedures helped me to properly understand the distinct specs of both for the global benefit of my golf game!
Now, regarding your question about distance, I produce rougthly the same distances with both procedures - long to short irons.
I love
driving my club into the ground while hitting. But with long irons, the
arc of approach is not as steep with wedges. As a result I
copiously drive it down to low point as I want to feel a nice contact with the ground I love so much!
This might be the reason you are striving with hitting your long irons a long way: Aren't you forfeiting the "down" because you see a ball positioned more forward in your stance?
Distance is also related to Lag pressure: Do you put and sustain enough lag pressure on your downstroke? I know that when I hit I tend to feel
much more Lag pressure than when Swinging.