I have two miu 600 with the corresponding housing. I bought them in March and I have used them maybe 20 times (no student use and I am very diligent with the o-rings and the treatment of the cameras!!). One of them is ALREADY leaking at the lense and one is overall always very damp at the end of the dive! I am immensly disappointed as I have a sony camera with housing (for over 1 year now) and I use it for students and it has already done at least a 100 dives (!!!!) and it never leaked even the tiniest bit, and even without silicone gel pack it is always dry!!!!
I bought two because they were recommended to me - from PADI Europe and the person who wrote the PADI Digital Underwater photography manual.
Unfortunately, I have friends owning a dives school and they have exactly the same problem as I have with exactly the same cameras!
Good thing I bought them from PADI and thus I got a one year flooding garuantee on both cameras. Shame I can’t get my money back and buy myself two Sony W1 (I know they just have 5m pixels and it is older - but the pics are better than with the mju 600 as well - on land and underwater) instead, they would have been cheaper and better!!!