I have both. My PW 800+ is electric drive, my MEC 9000 is hydraulic. Both are good machines. Neither is a good reloader for a person new to reloading.
The MEC is faster than PW if you that makes much difference to you.
The MEC is much easier to correct a jam or other problem. The PW can be pretty tricky but once you get to know the machine it is not bad.
The PW is a much more of a machine, few stamped parts, unlike the MEC. Like comparing a Win. Model 12 to a Rem. 870. Both will do the job ----
The biggest advantage to the PW 800+ is you can change to any guage, 20, 28, 410, by the purchase of the a guage change set for about $300 new, somewhat less than that used.
My 2 cents worth. Regards, Bob