[quackle] quackle playing strength?

[marc_roddis]

Hello,
I'm very interested to know what you estimate the playing strength of 
quackle to be.  Is there a big difference between the playing strength 
of the different players (speedy, 20 second, 5 minute)?  I'm not really 
good enough at scrabble to be able to estimate the playing strength 
myself.
Marc