I have a 1642 Jet. I upgraded to the 2 HP motor to be on-par, power-wise, with the PMs.
As for doing larger bowls, the sliding headstock allows you to move it to the end of the bed and go as big as you can mange. Still, the bed is not as beefy as the PM, so large and out-of-balance pieces start to shake the lathe earlier than they would on a heavier lathe.
If you never need to move your lathe the PM models are so much heavier than the Jet I think you'd need a forklift. I need to move my lathe around the garage so I put a heavy-duty machinery mover kit (the heavy-dutiest one that Jet sells) on mine. It is not designed for lathes, so I had to weld reinforcements to stabilize the dolly wheels. As it is, I am sure it could not take another X00 pounds+ of a Powermatic.