Since migrating to DPM 2010, I have an hour a day back. Seven hours a week isn't trivial (it couldn't go a weekend day without being looked at either). With DPM 2007, there were days where I spent much more than an hour coaxing it into behaving itself for the next day, and the alerts were both not tunable, and too chatty to be useful. With DPM 2007, even using the DPM powershell extensions to run scheduled contingent consistency checks, and hourly runs of pruneshadow copies, I was forever fiddling with things that went pear shaped. Still, centralizing the SQL backups was worth it, I just hoped it would get better in 2010, and it really, really did.
I moved the last 2007 out of the environment last month, and my life is suddenly *way* easier.
In DPM 2007, it just plain couldn't keep up with pruning and I frequently ended up with protection groups containing *way* more recovery points than I had specified. Even with an hourly run of pruneshadow copies, I frequently had to brute force it by kicking off multiple concurrent prunes just to get it to catch itself up. On 2010, with the same retention and number of databases, I'm not even running pruning as a scheduled job, it just keeps up.
In DPM 2007, replicas were forever getting inconsistent with the slightest provocation. If creating a recovery point timed out, boom, inconsistent and the job to run consistency check didn't always fix it. More than once, I had to destroy and rebuild the replica (*so* not ideal). after multiple cumbersomely disk intensive consistency checks failed to fix the problem. DPM 2010 self-heals nicely.
I'm also not seeing agent crashes, even on 2003/2005 servers.
I have an hour a day back from fighting DPM problems, pretty nice!