Re: opinion wanted on this small set of puzzles
As a seasoned calcudoku.org puzzler I find these puzzles comparatively easy but still entertaining because of the (small, manageable) challenges they pose. But then many of the restrictions I initially became aware of through conscious analysis, however simple (such as "the number 3 never goes into a 2: cage in a puzzle whose dimensions are less than 6x6", "upper and lower bounds often dictate which number combinations are possible in cages", the parity rule etc.), are now part of my "gut feeling" so that I can look for opportunities to utilize them in a given puzzle simultaneously and consider possible combinations of them rather intuitively. Maybe I would have found these puzzles annoyingly hard back when all I had tried in this genre was a few dozen not-too-hard kenkens. Or maybe I would have liked the increased complexity of the analysis necessary to solve them.
In fact, complexity is probably what I find appealing (and believe I would have found appealing even as a newbie kenken solver) about these puzzles: Many easy kenkens/whatever-dokus
can be solved by making a series of very simple inferences
sequentially (which may soon become tedious) whereas these puzzles give you the feeling that you have to consider several things
simultaneously (grasp a larger context) to get to the solution. I don't know if the K-dokus in the Volkskrant are of the former kind but if they are, many of the current Krant puzzlers may welcome the challenge.