This cam has way more overlap than the factory cam for sure. Depending on which factory hemi cam we're talkin about, they can be -30* or even more negative. It should sound more lumpy at idle for sure as you have noted that the overlap will cause more intake tract reversion.
Here are some rough overlap numbers for real world comparison:
The 5.7 hemi: -33* (depending on vehicle).
The 6.4 hemi: -22* (charger/challenger).
The 6.2 house cat: -13*.
These are at idle before VVT has kicked in of course...but so you have an idea since you can hear those idling while out driving and such.
The Hughes whiplash: +15*.
The COMP Thumpr for older small blocks: +19*.