> Yeah but can I get a metric ton of benchmarks at that 45w setpoint?

Yup, they're out there.

> I don't really see the reason in paying for a 100w TDP premium if I'm just going to scale it down to 65w.

You might want the core count or peak performance for the very short term. When I was looking, running 65W parts in the 45W envelope was only about a 7% penalty, so you get a bunch more performance/watt.