I will say that I actually don't like the newer style bassinets - they're all enclosed and they don't seem to allow any airflow.

I used an older style one with my kids (the woven cane type ones) because I had summer babies and I'm in Brisbane it's too damn hot to put them in anything else! I bought brand new mattresses when each of them were born.

As far as I understand it, in terms of the SIDS risk (which is what you're asking about I think?!) it's the mattress that is the issue, not the actual cot or bassinette itself. Although obviously you wouldn't put a baby in a bassinet that's been sitting in someone's garage gathering dust for 20 years either.