The difference in sweet spot size, and in the usable hitting area, are small; the difference in power is a bit more significant.
But the biggest difference is how much you can close the racquet face, and not hit the frame. This is an interesting article about that concept: The inch that changed tennis forever
This illustration from the article shows how you could close the face on a modern racquet by 35 degrees, and still have the same margin for error you had with a vertical face on a wood racquet: