I have just bought a new GM Paragon (separate thread, with pics, will follow), from a major GM retailer in Nottingham. I was advised to spend around 45 minutes knocking the edges in. I am glad I did - there has been a considerable amount of 'rounding' of the edges, such that the scuff sheet edges have had to be removed and re-laid. This shows a fair bit of softness around the edge. The central portion of the blade also shows some indentations after some mallet work.
Unless you are buying a bat at the last minute - on the way to your match, I think you should enjoy the knocking in process, to satisfy yourself it is 'ready to play', (even if that may take less time with a GM).
David