UPDATE December 2020:
After listening to this disc again, a couple of years later, with fresh ears, I've upgraded my previous review a bit. I simply enjoyed it much more this time around than previously.
There is no denying the benefit of Pentatone's superlative SACD sound here. And while Ulf-Dieter Schaaff is still just a touch bland in places, mostly in quieter passages, the overall playing of all involved really is quite nice. So, if not a first choice, it's certainly worthy of retaining a place on the shelf.
Original review (slightly abridged):
There is nothing at all wrong with the playing here. And Pentatone's sound is certainly great in SACD - clear, clean, brightly lit and intimately focused.
Throughout the entire disc, I found tempi to be perfectly judged and the playing crisp and alert. With the best flutists, these can be some of Mozart's most charming creations. But Ulf-Dieter Schaaff's tone in softer passages tends to lack the vibrancy which should allow this music to spring to life. And, conversely, in forte passages, he tends to play with a slightly forced/overblown quality which pushes his pitch ever-so-slightly sharp. His clear, clean, bright sound should work well in Mozart; yet in its very clarity, it can sound detached and slightly cold.
I must hasten to add that I have nothing but praise for the fabulous trio of string players with whom he plays. Mr. Schaaff is the principal flutist of the Berlin Radio Symphony Orchestra (RSB) and he handpicked these players from within the ranks of that orchestra. Their playing is characterful, articulate, and at all times extremely musically stylish and alert.
The recording by Oxalys, on the Fuga Libera label, is the best of all in these works. And any other reading of them will be difficult to match. But Ulf-Dieter Schaaff and friends provide an uplifting experience, aided by fantastic sound. And I admit not being as bothered by his tone as previously. That being said, I'd love to hear Mr. Schaaff in some 20th-Century flute repertoire (Ibert, Jolivet, Martin, etc.). If he's got the technical chops for this extremely difficult music, I can imagine his clear, bright sound would be splendidly suited to it. What a terrific follow-up recording that might be - perhaps with his own RSB orchestra.
Meanwhile, this Mozart is rewarding - especially so in SACD.