I actually used those certs and miss them SO much! My best uses of SSWU were YVR-SYD and SYD-YVR. I used KVS (is that still a thing?) to pick my dates strategically as a 35k (which was useful back then).

I remember being on a flight back with Mrs. PITUK LHR-YVR in J (I didn't pay for J, so I assume it was SWUs). The guy across from me was buying something expensive from duty free, so I offered him the discount coupon that we had. Turns out he was a SE who always paid for J J and said 'thanks' and gave me all his SWUs and SSWUs since he couldn't use them.

Good times.
Dr. PITUK