What Mark said. I know there's lots of threads on issues, but I tend to think that's because the products are so widely used - the more people using them, the more likely we're going to hear about errors of some sort or another (manufacturing, user, etc.).
That said, I've had all the ProTank products, and have never, ever - not even once! - had an issue with flooding or gurgling. I'd advise to check your set-up, make sure everything is always clean and fitting properly, read a few threads on problem solving, etc. before you throw the tanks away.
On the other hand, if you find another set-up that works for you with less hassle, then just go with that - no need to use the "latest and greatest" or most popular device!