I think John F in the posts above pretty much nailed it. I have both the 18.2 Delite and Panoptic 19, and have used both in the Q 3.5. Both are really good oculars and the differences are minimal. The Panoptic has a little wider apparent field, a little smaller and lighter, and eye relief a little too short for my glasses. The Delite has adequate eye relief for glasses, and can accept Dioptrix without an adapter, but a lot larger. They are both very sharp optically. Both came to focus in the Q finder, but the Panoptic had a little more focusing tolerance. I use the a Delite with a Dioptrix mostly in a fast scope where astigmatism is a factor, and the Panoptic in slower scopes such as the Q.
Like Optics Patent, I feel there is not something quite right about sticking a big hulking eyepiece into a Q. The Brandons also accept the winged eye guards I like to use to block ambient light pollution and improve contrast with deep sky objects. I’ve tried different eyepieces with the Q, but Brandons provide the most pleasing image for me.
Mike - Where/how can one get such winged eye guards? There is a light at my observing site that needs blocking. Thanks!