I use the Mollenhauer 2546K Canta Bass in a small recorder ensemble, mostly for playing duets and quartets. I also have a Canta Soprano, Alto, Knick Comfort Tenor and Knick Great Bass. It is a good series of satisfying recorders.
The instrument is good to look at and is nicely put together. The case is an excellent fit and neither too bulky nor too heavy.
The sound response is good and the instrument is not difficult to play. The windway tends to clog with water very quickly, much more so than any of the three plastic basses I played formerly (an Aulos bocal-blown and two different Yamaha Knick instruments). This is a disadvantage in a long piece, as one needs to clear out the water before the instrument stops altogether! The sound is a little more "husky" than I had expected and I am wondering whether to return the instrument to Mollenhuaer for adjustment.
What I really do not like is the fact that the F / F# keys are counter intuitive: one key for F natural, both keys for F#. It is the same on my comfort knick tenor by Mollenhauer, but surprisingly the knick great bass is the other way round. Very confusing when I have to swap instruments from item to item. I can't think why Mollenhauer did that when most recorder players are used to double holes for C / C# and D / D# on sopranos and tenors, F / F# and G / G# on altos, which work in what I would call int he intuitive way, namely, you cover one hole for the # and two holes for the natural.
Overall, I am fairly happy with the recorder and can recommend it to others as good value for money.