I have to say all of the netgear routers I've had seem to run warm.
The Billion I'm now using is warm to the touch over one part but does appear to be better ventilated.
Virgin (ADSL) => Namesco => Newnet => O2 => Plusnet => Zen => Newnet => Zen => Freeola => Vivaciti (using O2 Wholesale DSL) => Xilo (C&W Wholesale) => Xilo (O2 Wholesale)
Note: I don't lay turf for anyone. astro or otherwise, all views and opinions expressed are my own based on experience.