Trying to decide between a few backpack blowers. Stihl BR 420 D, Kawasaki KRB650B, Echo PB-620, and the Redmax EB4401. Stihl= 56.5 cc engine 518 cfm's @ the tube 172 mph Kawasaki= 45.4 cc engine 580 cfm's @ the tube 164 mph Echo= 58.2 cc engine 530 cfm's @ the tube 185 mph Redmax= 41.5 cc engine 671 cfm's @ the tube 183 mph Now the Redmax has the smallest engine, how in the h#$@ is it moving more air than the others, this info came from their website. Does anyone have any of these units or experience with them and can make any truth to this? Because if this is correct, then the Redmax is a no brainer for purchase it is also the cheaper of the four @ $349.99 and tax. Are they reliable, durable and dependable? Need your help guys.