I also think QSelect in 1.0 is somewhat a downgrade. Somehow it doesn’t behave well and is more difficult to use. It feels like 0.17 popups behaved more consistently (looked more professionally), there were options with enabling checkboxes and a relatively simple search, and the entire api was simpler to use.
It would be nice if somehow a reincarnation of 0.17 QSelect was included to 1.x under a different name (QSimpleSelect?), and I’d be even willing to pay for this feature.