I say electric over hydraulic but meant only electric motor. Was thinking of something else on a woodmizer not sure why I said that. The 4500 uses electric motor only to raise the head up and down. Which is much slower than a hydraulic cylinder moved head. My head from bottom to top takes 5 seconds. A 4500 takes 8.7-9 seconds.

Many factors go into buying a sawmill. Things to consider are legit production rates for your set up.
What it cost to get those bf per hour have many factors.
You can get a setup like mine for $50000-100000 less than a 4500. With little too no difference in production numbers in matching setups.
For a 4500 to make since it would need to be able to produce enough lumber over the super 70. To cover the initial investment upfront. Along with getting 3 phase installed. Your blade cost is also higher on a 4500.
Don’t get me wrong I want to install a 4500 now. But I know it wouldn’t put more money in my pocket.