The 20-minute power nap has become the perfect power nap for me. The 25 minute PN is also good but can result in some grogginess upon waking.  The 6 minute is a good, quick, re-boot -but usually does carry the same effect as the 20.  Thank YOU for posting these.  I listen to your 20-minute nap every single day now -between 3 pm and 4:30 pm.  Wow!
Awesome! Perfect! Thanks, Carl!
Carl Martin