Anyone have two bodies & have them have a different shutter sound?

So a few months ago I had a problem with my 5D3's having different shutter sounds after sending it in got a shutter repair once, so I sent it in again and they fixed it but didn't tell me what the cause of the problem was.


So now after taking advantage of the incredible price decrease on the 1DX with the MK2 coming out I went ahead and purchased a new one & noticed the shutter sounded completely different to the one I already owned since October, it's... best described as less clicky? and more of a deeper sound, I've tried shooting off a few bursts at 12fps to see if it's affecting anything and so far 9/10 tries have been that it would take 31 pictures and the newer one would take 32-33.

Does anyone else have this problem & should I send it in to cps or just ignore & and accept it's because it's a older camera with close to 45k shutter shots?