Been playing for years, and I've still got Dunlops on some of my guitars and Schallers on a few basses.
For all regular use, rubber washers function just as well as Dunlops and Schallers, and they have a couple real advantages. On vintage instruments, they let you keep the original strap button and screw installed. And besides costing just pennies, they are also low-profile. Some guitar cases don't allow clearance for Schallers or Dunlops, so you have to take the strap off to case the instrument--increasing the chances that you'll leave the strap somewhere and/or misplace the top part of the Schaller-style locks. With rubber washers, I can leave my straps on in transit.
Seriously, unless you regularly spin your bass around-the-world, rubber washers win. And, of course, even if you do spin, Schallers and Dunlops won't save you when the strap-button screw rips out of the bass.