Has anyone done any SLA metrics in contracts for Managed Print Services?

Following could be SLA matrix for Printing Services:

1. Uptime per printer

2. Repair Time should not be more than 2 days (Repair time = Date on which printer made operational - Date on which the Incidence lodged)

But also, beware of:

1. Late Payment Charges, Insurance Charges
2. Avoid automatic renewal
3. Pick Up and Movement of printer should be vendor's responsibility
4. Do not commit to minimum printing volume
5. Always invite competitive bids

We had some standard mean time to repair, and delivery of supplies that included paper. Since many of our buildings were large they could have one printer down per floor unless there were more than 8 in which case they could have two down. There was a lot of variation in our buildings. I never felt SLA penalties were the way to go. Getting your money back is hard. Instead reward. If no printer outages reported then a $$$ reward for the month. IMHO

What type of Managed Print Services are we talking about? Could you give an example?