The only draw back that I have ever encountered, is that if the model sits for an extended period, they sometimes split at the seems. I guess the fuel gets to the plastic and causes that. I just make it a habit of checking the tank before I fly a stored model. It's another good reason to always make your tank compartment fuel proof and easily accessable. The good part of this is to replace it, just purchase the proper tank, take the old plumbing and put it in the new tank. The material that Sullivan is making their stppers out of lives a fairly long time and allows this.
I use the plastic tanks frequently, on bothe built up and profile airplanes.
Type at you later,
Dan McEntee