Just how 'hao' is your Chinese?

Recently I was told by a Chinese friend that my spoken Chinese was "非常非常不错." In English, this literally translates to "very, very not bad," so it was hard to interpret this as a compliment. I asked a few other Chinese speakers, who assured me that "非常非常不错" was a strong compliment, so I started wondering – what were the differences between "挺好" and "很好" or all the other ways one could assess something. In order from worst to best, here's a cheat sheet of ways to express your feelings, and how to interpret put-downs or compliments from Chinese speakers.

Negative

特别糟糕 (tèbié zāogāo) -Exceptionally bad/particularly bad. Chinese people are pretty polite to those that try to learn their language, and that includes lots of compliments. Your Chinese would be "特别糟糕 " if you tried to speak a completely different language and tried to pass it off as Chinese. Or every time you say "shay shay" instead of "xièxiè."

非常不好(fēicháng bù hǎo) – Similarly to the above, there is little chance that someone will tell you your Chinese is 非常不好 unless you've really pissed them off. Maybe if you broke up with your Chinese girlfriend who you were only using to practice your language, she'd tell you your speaking is "非常不好."

不太好 (bú tài hǎo)– Not too good. Expect this as an honest assessment from friends, or a teacher you can joke with.

Neutral

马马虎虎 (mǎmǎhūhū)– So-so–an average or noncommittal opinion. Many beginner textbooks teach this word, but I've never heard anyone use it in real life.

还好 (háihǎo) – Not bad, passable. Sometimes can be used to mean, "It could be worse."

还可以 (háikěyǐ) and可以 (kěyǐ)–It's acceptable, but the meaning here is all in voice tone. With a flat voice, 可以 can indicate, "You've done the bare minimum to be acceptable" but with a cheerful tone it means, "Yeah, that's fine!"

挺好 (tǐng hǎo)– The most neutral "pretty good" you can muster.