The best SFI Power Tools are the ones which bring good results with small effort/investment
I appreciate a lot the Power of 1 T-Credit which brings 102 VersaPoints for less than 2 $ and the power of W3 program which brings monthly 5 T-Credits and 50 MRPs for one time payment of 1.95 $
Also, I have been pretty lucky till now in winning 2 T-Credits in the hourly lottery and I like a lot the possibility to convert 1 T-Credit into 10 MRPs by participating in Pricebender Auctions.