My first set of speed rings (with Elinchrom insert) were also from eBay. As mentioned, they sucked. I replaced them with Calumet speed rings (with their Elinchrom insert) and the quality is much better.
HOWEVER... I do have an issue even with Calumet product (the Elinchrom insert, specifically). For some very strange reason, only one of the mounting slots in the Elinchrom insert will properly lock onto my D-Lite 4s. Example: I'll call the two slots (cutouts) in the insert slot A and slot B. If I install the insert onto my D-Lite with slot A near the D-Lite's sliding lock lever, and then lock the lever, the insert can STILL be turned counterclockwise (facing the flash tube) and pulled out of the D-Lite (accidentally or otherwise). However, if I rotate the insert 180º and install slot B closest to the sliding lock lever, the insert stays put when the lock lever is turned to lock.
It's the strangest damn thing! The slots in the Elinchrom insert appear to be absolutely identical. Yet, installed one way they won't properly lock and install the other way they lock perfectly. This is consistent across all three Calumet speed rings/Elinchrom inserts that I own and I've tried them all in three different D-Lite 4s with the same results.
Now somebody explain THAT one to me! (And I'd be curious if anyone else is experiencing this with other brands of Elinchrom inserts??)
Mark
"If a day goes by without my doing something related to photography, it's as though I've neglected something essential to my existence, as though I had forgotten to wake up."
-- Richard Avedon