I think it varies with both fork and conditions. My dual suspension MTB has an air fork and on pavement I really notice a difference between locked and unlocked. My hardtail MTB commuter had a less noticeable difference between locked and unlocked, but the main reason for converting it to a steel rigid fork was weight.
If your commuting route resembles a blasted moonscape then suspension makes sense , as do fat tires. On smooth pavement suspension is mostly just weight and complexity.