German language:
https://www.bonedo.de/artikel/einzelansicht/bose-s1-pro-test.html

Rated 4 of 5 stars.
The bass is supposed to struggle with modern dance music if turned too loud.
The reviewer considers it to be adequate for a noisy audience of 25 people.

Google translation of the review summary:

Conclusion (4/5)
With the S1 Pro, Bose closes the gap between their consumer series and the PA line. The shoe box-sized box is equipped with a three-channel mixer including Bluetooth, ToneMatch, Reverb, EQ and Spatial Dispersion and weighs just seven kilograms. The optional battery makes the box independent of the power outlet and you are free in the choice of the venue. The volume is sufficient for 25 party people or 40 attentive listeners, the sound automatically following the four setup options. The sound is always good and full, as usual with Bose. For 589 euros (without battery), the box as a handy, transportable sound solution for singer / songwriter and speaker and limited as a small DJ system. You should not expect subbasses, however, with contemporary dance music the S1 Pro has its problems. Nevertheless, I find the overall package very convincing and give the system 4 stars.

PRO
light, very handy box
excellent resolution of the sound
automatic master EQ for four applications
Three channel mixer
ToneMatch presets for Micro & Hi-Z
Reverb (Channel 1 & 2)
feedback-resistant
optional battery
CONTRA
Bass flutters with dance music
Volume control shows delayed reaction
Hi-Z slices
difficult to estimate residual charge of the battery

Again , much to expensive Label Bose ( also made in China ) , but if you search a nice smal affordabel set look at this >
https://www.bonedo.de/artikel/einzelansicht/ld-systems-dave-8-roadie-test/3.html
and this is also much for less ( i own it , and it sounds Great)
https://www.bonedo.de/artikel/einzelansicht/the-box-pro-achat-mini-bundle-test.html

Impuls

I’ll test mine out this week.

My cousin decided to keep the S1 he was trying out. He told me that it worked well for him, 50 folks in a mid sized room.

User reviews.

https://www.sweetwater.com/store/detail/S1Pro/reviews

I posted in the Genos PSR forum about this; I bought one Bose S1. It has surprisingly good sound, IMHO, for its size. Way better than a battery-powered Behringer I had been using (BT40 Pro or something like that). I tried it in 3 of the "orientations" and I could hear changes in the EQ. First I just it on the floor then a table, sounded best - full amount of bass etc. Tilted it back, aiming it "up", it had slightly less bass but still sounded very good. When I put it in "Floor monitor/wegde" position, I think they increase the "mids" a bit too much for my taste, got a bit "screechy", at least on a couple of tracks I listened to. Didn't have the feeling of mids being too high or screechy in the other positions; it sounded great in those positions. Maybe in floor monitor mode they increase the mids to help with vocal monitoring?

I'm hoping it will be good for me for things like practices, jam sessions / parties, small gigs ...

Jim

Up to 44 reviews Sweetwater site. 4.5 stars.

I check that review page regularly. Even a pastor in Central Montana got his S1 Pro now and is happy about it