Hi Christian, I handled quite some Tina knives as I worked on a knife catalogue and had to take pictures of some of the knives too.
All models were very sharp, as a matter of fact also the hawkbill/pruner style knives. And that's not always the case, as this means to treat them specifically by hand with convex stones.
You may find all models (or almost all) to be finished with a very acute slight convex edge which may be maintained by "mousepad and sand paper"-sharpening.
I actually changed my grind and did a compound bevel 15° and 20° on top on the left edge.
Finally the right edge is then only stropped a few times (alternately with the left edge) to remove the burr. That works good for me and builds a long lasting edge.