Check this out:
I just upgraded my mail cluster server. I need to upgrade my app cluster now. I'm going to dive more into DDM now! I'm really pumped about DDM for some reason.
The upgrade from 6.5.4 went well. The RSTLICPGM took about 20 minutes total and the UPDDOMSVR took 5 minutes. This is on a 2-way 270 Dedicated Server for Domino. On my 4-way 820 iSeries it should only take about 7 minutes total judging from past upgrades!
I'm planning on also taking some CPU snapshots for the next several weeks on my production box to see how the 7.0 upgrade fares in a production environment.