It is hard to say. George was not a bad person. (at least as king. Now as a parent, well that is another story.) He was not the brightest either. Even though he is given by some historians the edge on his elder brother the Duke of Clarence on intelligence, (apparently most of their contemporaries and even some revisonists say there was not much difference between the two, nice men, just not so smart) but then again George was a constitutional monarch. He did not have to make the decisions necessary to rule. No which ever one inherited the throne, in real life's case, it was George, he learned his kingship from his father Edward VII. But if Edward VII predeceases George as did his elder brother, then Britain is left with a monarch who has spent most his life expecting someone else to be king.
My guess is that George V would have been what he was, a good constitutional monarch but wold have not been able to have as much influence as his father who was a socialite, more of a people person, who commanded a respect from his fellow monarchs, including a begrudging one from his nephew the Kaiser. George's biggest asset was that he was the symbol of the British Empire. So the loss of an Edwardian period, even though he too was a constitutional monarch, could have had some serious repercussions on history.