The current generation of plastic, like better bottle, are not more porous. They do not allow oxygen to permiate. They are also supposed to be safe from absorbing odors. They do scratch easier. I have plenty of glass, but I have some very good brewing friends who use the better bottles. As long as it is the right kind of plastic, it is fine.

I have installed 2 17 gallon plastic conical fermentors to use as primaries. So far I like them. Time will tell if they are durable enough.