Those are machines that someone who was really, really good could probably get the job done with in a dire emergency. For anyone else, they're torture devices.
Considering that you can get a perfectly good Lincoln 225 amp AC buzz box for under $100 on craigslist (my niece paid $50 for one in March), I see no reason to make yourself use such difficult equipment. 45 volts open circuit voltage is so low that you'll constantly have trouble striking and maintaining an arc. You'll find that 6013 rod works better than anything else, so you'll always use that---and 6013 is just not that good a choice.