I have Nook Color, Nook Tablet (16 GB), Kindle Fire and Google Nexus 7. I find that the Nook Tablet and Google Nexus 7 are much faster than the Nook Color and Kindle Fire.
It will be interesting to see what happens with the new devices coming out this fall. My guess is we will see new Nook Tablets, Kindle Fire 2 and the mini iPad all trying to compete against each other.
The bonus is - we are the winners in this war.