The main benefit is less chance of the isolator warping and causing an air leak. I put an alloy intake manifold on my engine last year after running the phenolic intake for several years. I noticed the aluminum one was leaking so retorqued it and it stayed sealed after that. I also suspect that on a hot day last summer the aluminum manifold transferred too much heat to the carb causing the motor to kill during a race heat. I built a new engine for this season and am trying the RB Innovations manifold with heat sinks and diaphragm filter, we'll see how it does in the heat of the mid summer.