I'm going to use the bronze thrust washers for my current rebuild. Roller bearings are too expensive and don't look to be as durable as a simple washer. I can't imagine what would happen if one (or more) of those rollers got out of the cage.
To answer the question as it was asked.
Some people have worn out the rollers in only a few years (there was pictures of them on the internet) so they replaced them with bronze washers.
Of course, the pinion bearing is another story. I tried the stock version, then went with the Fun Projects replacement. Any future rear axles I rebuild will get the FP bearing.