Whilst it's absolutely more time consuming, I'd probably prefer a clean install. I don't do a lot of disaster recovery though so one off here and there doesn't irk me much.

I've only done limited Crashplan restores from the cloud and locally but every spot check I've done on total files, checking logs of new files backed up and so has checked out. The process is a bit heavy being Java only and it does need a bit of RAM to run on a NAS with millions of files but it does the job well and "just work" (tm). I have about 1.4TB compressed in their cloud (took 6+ months on <1Mbit upstream connection)