Interesting they went with 120v since higher voltage, at least that high, can in many ways have short comings in terms of package size and weight. More battery cells are needed, which means more cell dividing material which equals less space efficiency, larger insulators/gaps needed for high voltage, not to mention that safety risks of systems higher than 70v. Capacitors have a major trade off in capacity per size with an increase in voltage handling, similar with the transistors that control throttle. 30v and 60v setups tend to get you the most power for the size and weight as far as I know from my dealings with electric motors and controllers, but there is another not so sweet sweet spot around the voltage produced by 35 lithium cells: a bit more than 120v.
As for comparisons, you can't judge power by voltage alone, which is likely more of a selling point. A 3.7v saw could easily out cut that 120v saw in the same size package, but who wants an odd 3.7v power tool?
Corded models could be easily out performed by battery models depending on the power of the battery model, because the corded ones will be limited to a safe max amperage as to not burn extension cords, outlets, and trip breakers. I'd figure you couldn't hope for much more than 1.5hp to the chain on a corded model considering the efficiency losses in the motor. I could only guesstimate the 120v saw could peak 2.5hp more or less, potentially, but not likely much more. At least low end torque is on your side with electrics.
