Thanks for all the comments.
I went ahead and bought the Aulos 501S garklein (arrived today). Here are some impressions:
– first of all, as expected from Aulos, it’s a very high-quality instrument, even though it’s plastic. I checked it with a tuner and it’s perfectly in tune. Very well manufactured, no flaws of any kind.
– it’s extremely small and the holes are very close together. I wear S-size gloves, I have relatively small hands with thin bony fingers, and I can barely squeeze my fingers together to cover the holes. Do not buy this if you are the chubby type, with thick “sausage-like” fingers, you probably won’t be able to play it at all.
– the sound is high-pitch and piercingly loud. As most of you are well aware, it’s an octave higher than the soprano, but it’s brighter and more shrill than the higher octave of the soprano. Furthermore, the notes from its own higher octave are almost unbearably, damagingly trebly and loud. Most likely you will be playing in the lower register most of the time. It’s funny to call this the “lower” register, because it’s anything but low.
So the question is, should you buy it? I say yes. It’s a great value! I thought it was expensive at first, but it’s VERY well made. It’s also lots of fun, not to mention highly portable. Also, my wife thinks it’s cute (we’re still talking about the recorder).