We've had to revert doing exactly that in the past. (We just recently had to back out a failed upgrade from 6.61 to 6.7 by using the snapshot and had no problems.) I see no reason why it should work from 6.0 to 6.61
The only precaution to take is to ensure you stop the vROps cluster before you take the snapshot. In that case, there are no consistency concerns with any of the databases.