Intensifiers of comparatives in negative sentences

[sitifan]

1. The food wasn't much better than I expected.
2. The food wasn't a lot better than I expected.
3. The food wasn't even better than I expected.
4. The food wasn't still better than I expected.
5. The food wasn't a little better than I expected.
6. The food wasn't a bit better than I expected.
Which of the above sentences is NOT acceptable?

[Tdol]

What do you mean by acceptable? Some are close to meaningless or highly unnatural but grammatically OK.