I have 200+ dives on various ikelite housings, zero issues.. The salt content of the water where I dive is also higher than most places, so housings take a beating.
That being said when it is time for me to upgrade cameras, I will do all calculations and considerations of purchasing an aluminum housing. I have no real reason to go with anyone but ikelite as I already have ports and what not, however as they say the grass is always greener on the other side. I would be doing myself an injustice if I don't at least check out the other manufacturers.
in my mind Ikelite has an advantage in that they are an american company.