Most often it is a question of bonding more than machine ability.
The other issue with vintage machines, they are like used cars, and while one may have been a clear winner if both where NEW - the winner now may be the one that had better care or less use overall.
I have a Viking 990 that I've loved for years, but after 35 it wouldn't quite hold a straight stitch due to wear. So when the choice was between that one and a 20 year old Pfaff - the Pfaff was the winner. However I got lucky on eBay, and snagged an unused (yes, totally unused) 990. My husband liked the Pfaff better than any of his other machines, so now he has that one, and the Singer 201 and 401 went out to the shed.