I think it helps the defense in a few different ways...
One, there is the elimination of stealing hand signals.
However, what about the possibility of stealing radio signals?
I think it gives the coach and in our case the MLB, EJ a bit more communication.
The coach can say more than just the play call...a little insight into what to look for in certain situations, or maybe, the guy upstairs calls down to the sidelines with a we saw this formation on the tape kind of call.
And, the info should be more complete, the variations less likely to be misinterpreted.
Also, seems to me, that the play will come in quicker...that the headset guy can be giving the info to the rest of the team quicker than if he had to watch a series of hand signals on the sideline.
He can be watching the O set up and listening to the play call at the same time.
Maybe most importantly, it should help the D vs. the No-huddle offense.
Still won't be much time to set up, but at least there could be some input from the sidelines.
A concern of mine, is injuries and equipment malfunction.
For over 20 years I've been involved someway in the restaurant industry, so I've seen all manners of written and computer order systems.
Seems that all computer systems go down from time to time, and what used to be the way it was done (written orders), now throws servers and kitchens into chaos.
As we rely more and more on technology, we handle life without less comfortably.
What happens when a helmet takes a beating and there's a loose wire, or a player has to leave the field and somebody forgets to switch helmets...?
All in all, I feel it does even out the offensive advantage somewhat.
However, the "no push out" rule will probably help more, as it makes those sideline catches quite a bit harder to come down with.