I changed my grip more strong recently, and it was a revelation after being too flat for years. A guy at the range had one of those training aid 8 irons that weigh a ton with the moulded grip on it, and I had a go. Couldn't believe how wrong I was with the grip all these years, and no coach ever tackled it.
I don't mind being flatter if I'm hitting the ball well, and I know it was because of my grip on the club. Just didn't know where to place my right hand. Did my head in all the time. So i'd swing up, and almost feel the grip slip in my right hand. Now it just sits there and doesn't move in the backswing.
My buddy commented saying that I wasn't looking as flat, and I'll be honest, I had no idea it even changed.