I just posted this elsewhere:
Dip (left), Tet (right):
There are some articles and threads on the subject.
I forget most of the info. But cold hardiness can improve.
Flowers can get "stiffer" as can scapes. This may be seen as a downside in cases. Patterns may potentially be lost, or change. And fertility may be reduced or destroyed depending on how well the conversion takes place, it may lose fertility one way round (pollen is OK for my tet pink stripes so pod must be the problem).
If I remember more, I will come back.
I think the conversions are mostly considered bridge plants to bring cool new features to the tet world (e.g. like tet RFK or tet Emerald Starburst did).
Here is an older post on fertility:
The thread "Do Tet Conversion Daylilies Require Special Growing Conditions?" in
Daylilies forum
Old blog
https://garden.org/blogs/entry...
