My brother in law recently ordered a set of Ping G425 irons to his specs from a local golf shop. I told him about the issue with Ping using Arccos in their grips and how the last 1/2 inch of the grip (that) there's no shaft there.
You can bend it with your thumb. So if you regrip without Arrcos the club will be 1/2 inch shorter.
Anyway, he called me yesterday and said he can feel it bend when he swings.
He talked to Ping about this and Ping is using 2 day shipping back and forth and will make the irons the correct length without Arccos.
They also told him they're getting some negative feedback on this as well. How the hell anyone at Ping thought this was a good idea is beyond me. Cobra uses Arccos, but there's no issue with the club being at a shorter length if regripped.
Also, Ping seems to still have issues with grips. Luckily he uses midsize because that's all they had in the standard Ping Grip.