Do you say "compared with" or "compared to"? For example, "plan A produced good results compared to/with plan B".
You can use both. Your example is matched by meaning 1:
1 (often compare to/with) estimate, measure, or note the similarity or dissimilarity between.
This car does not compare with the new Mercedes
This car cannot be compared to the new Mercedes
Shall I compare thee to a summer's day?
2 (compare to) point out or describe the resemblances of (something) with.
Emily compared her haircut to her friend's
3 (usu. compare with) be similar to or have a specified relationship with another thing or person.
Compare your responses with the answers