A generic appraisal for the Siebert Optics is this; I have the Ultra 17mm & 9mm + the Ultra 2x barlow.
I use the optics on my 12" F5 scope.
Star images are pinpoint and sharp to the edge, individually and combined.
Contrast is also excellent.
The other good feature is that the barrels are made of aluminium, making them a lot lighter than comparable e/p's.
If you're after a e/p that looks good from the outside, forget the Siebert they are rather plain looking.
But..........if external beauty doesn't worry you and you're after a very good performing(optically)e/p, then this is for you.
