I have a HRM and a cadence/speed sensor so I will continue to get an idea of the comparison. I guess I was hoping there was some sort of equation where level X resistance = X degrees of climb or something.

I'll ask this now, I've noticed that when I'm on a lower resistance but a higher gear (50-12), my trainer is loud as hell, but if I go with a higher resistance and a low gear like 34-28, the trainer is much more quiet. Both require the same effort and HR. Because it's so much quieter, I stay in easier gears with higher resistances. Is there any advantage to lowering the resistance and pedalling at higher speeds in harder gears?