I've got 2 Pfaff 7570s, and (from the same era) a Pfaff mechanical, which works just as well...but without the fancy features. Plus 2 Janome Sergers. My husband has a Singer Slant 403A (1959)...he just bought. I taught him how to sew, and now he's experimenting with leather. That machine is a tank!
I was just reading that a computerized machine draws more power in an RV.
But, to your point...the Pfaffs from that era are SUPER lightweight; yet they've got a lot of power, and can handle layers and stuff because of the IDT system.
I got my 2nd 7570 on Ebay...a super buy. It's actually 10 or so years newer than my other one...which is why I got it...for a back-up (I got panicky what with the Viking takeover of Pfaff and all). The person I bought it from had got it new...and then hardly ever used it. I got it for less than 20% of what they were going for new.
Those 7570s are best machines! They do embroidery, but I found I didn't really get much out of doing that...so I keep the EB unit...just because when you go to resell it...it commands more money if they are together. I had a brother Pacesetter (I think...
) from 1998...one of the first of the super home embroidery machines, and I wore it out...then realized it wasn't made that well, so traded it for my 1st 7570, which was made around the same time as that Brother. Difference of night and day, I tell ya!