Not good. Basically bankruptcy insurance, you pay for all your typical health expenses outside disaster. I don't know what Germany offers for that price, but given the overall lower cost of healthcare, presumably it actually covers your healthcare.
It's fairly good coverage without frills (i.e. you get a shared room in the hospital). Doctors tend to de-prioritize public insurance when giving appointments, because they earn less from them, particularly for elective or non-urgent issues, so you usually have to wait a bit longer than privately insured patients.
On the other hand, the insurance costs ~15% of income with a cap, so it has an element of solidarity to it - if you earn less, you pay less, and children and non-working spouse get covered without extra cost.
It's not public insurance though. It's private insurance companies on a given state's exchange which may be pretty similar to what you have through an employer. The big thing with Obamacare is that you can now get private insurance even with pre-conditions. I'm not going to especially defend health insurance in the US but the idea that you can only get it through an employer is just not true.