The Rebbe Shlita related that his grandfather the previous Rebbe ztz"l was at a sheva brachos where someone was heaping praise upon the chosson. At one point the person said that the chosson is the Rebbe Akiva Eiger of the next generation. This was too much for the Rebbe ztz"l. He protested "No, he's not!! It's not true!" There was only one Rebbe Akiva Eiger and frankly it is pure hyperbole to say that someone will be another.
One time Rav Simcha Zissel of Kelm was walking down the street and he heard someone playing the violon but his notes were off key. He knocked on the door and told the person that he didn't get it right. He could simply not tolerate anything that wasn't emes - even the playing of a violin. [Related by Rav Dov Katz in the sefer תנועות המוסר]
