Things I liked: Rear sight adjustments are positive and repeatable. Knobs work in service rifle directions---clockwise is up or right. Rear aperture is a good size, not too small, nor too large. Clicks are in 0.001" increments as checked with a dial indicator. Sight height adjustments are infinite, i.e., there are no notches that prevent setting the sight somewhere in between marks.
Things I would have changed: Have an option for a different sized front sight dovetail that will fit the Beeman R1, RWS break barrel guns, etc. Make the height marks a bit clearer, with scribed lines rather than dot matrix type lines. Also make a vernier scale on the sights to allow the repeat of settings without using calipers.
What others should know: Front sight base fits an 11mm dovetail, not the dovetail on many spring guns. The description that it fits the standard dovetail is somewhat ambiguous. I did make a spacer to allow the sight to be mounted on my Beeman R1 which works nicely. Note too, that the Lyman Anschutz sized inserts do not fit, there is no provision for the ears. Three acrylic inserts come with the sight, however.