Generally speaking, everything IS more with commercial. My feelings are that the systems tend to be more complicated, usage tends to be higher, so the need for service is higher. employee turnover means you will have training requirements and questions more often. Newer businesses may go under. This means the rate should show that. Plus, the chances of getting sued are higher as well if something does fail in your process.
The other side of the coin is maybe they should be the same but its your resi pricing that should go up to match your commercial price?