This small unit sounds great, the sound is rich and round. No harshness in high frequencies and very pleasant, powerful bass. (Yesssss, bass is really good!) Reverb is very nice. A bit of a pity that it has no chorus effect, for such a big price should have!
I use it for acoustic guitar in church choir and it really does the job. Amplification for this purpose is much enough, I drive it usually about 30 - 50% of gain and amplifier is LOUD. For practising 5 - 10% is enough.
Unfortunately in Thomann description there is no information that Acus One-Street5-W doesn't charge the battery... I found this info in papers enclosed to the unit... after purchasing. A little bit of dissapointment.
So if you consider to buy this amplifier you need to take into account not only additional costs for battery, but as well additional costs for a charger - all together (battery and charger) about 150 euro.
Producer recomends Makita batteries. Below I give you their numbers, I couldn't find this information before purchasing, so I think this may be helpful:
BATTERIES
6Ah - BL 1860B (or 632 G12-3)
5Ah - BL 1850B (or 632 F15-1)
3Ah - BL 1830B (or 197 422-4)
CHARGER
DC 18RC
Tip: Instead of buying separate battery and charger look for powertool set. I bought box with Makita driller, 2 batteries (5Ah) and charger for 185 euro. It is ridicoulus to buy driller, but this way is much cheeper :)