That's a tough one. I would say conservatively it takes me 25% less time to finish a job on average. Just going by the fact that half the job is setup and cleanup and using Festool has easily cut that time in half because it takes fewer trips to load my gear in and out as well as there is less setup required because of the dust collection.
Another big thing is keeping everyone happy, I charge a premium for these services and make much more money than I would taping a new house. The less I disturb the tenants the happier they are and if they are happy the management is happy. Because of this if I raise my prices a little they are much less likely to complain.
This isn't what I like doing but like I said it pays really well so I want to hold onto this client, on top of the increased profit it's also a lot easier on my body being lighter.