How long these Aisin built, chain drive CVTs will last is anyone's guess at this point. I would guess that they'll be as good, if not better than your average too many speed conventional automatic.
The EJ253 2.5i has been around forever. There's a zillion of them on the road. I don't know of any major advances in the cylinder heads and/or head gaskets on them like minuccims stated. I'm hoping head gaskets will last longer than on years past, but even the 'bad ones' typically lasted well beyond 100K miles before you had major leakage. It ain't cheap to have this fixed, since the engine basically has to come out if you want to do the job right.