On the Stihl web site, the specs for the BR550 and BR600 are close.
BR550---- BR600
64.8cc, 64.8cc
4 HP, 4 HP
Air Velocity 199mph, 201mph
Air volume
with tubes 530cfm, 712cfm
Air Volume
w/o tubes 877cfm, 1012cfm
Weight 21.4 lbs., 20.9 lbs.
In my opinion, volume(with tubes on) matters more than velocity so I would probably go with the BR600 if I was buying Stihl. Plus the more powerful blower weighs about a half pound less.
At the current time, the Stihl web site has a recall on some model BR500 and BR550 blower's. If you buy a BR550, make sure it isn't one of the recall serial number's. Stihl probably has taken the defective model's off the shelf.
There is no special service required for backpack blowers except making sure all screws and bolts are secure as they have a lot of vibration in the engine area and that holds true for all 2 stroke power equipment.
I never compared the new Stihl blower's with RedMax. I can, however, say that the Stihl BR400 I had was a great machine...troublefree. When comparing the Specs for the BR600 and EBZ8000, it appears that Stihl edges out the RedMax. /forums/images/graemlins/shocked.gif And the BR600 weighs about 4 lbs. less which would be a nice advantage.
I would probably drive to the tractor dealer and demo all three brands (if you have the time) to see how they compare in real life. If you decide to buy Stihl, you could buy from the dealer close to you. Or you could buy it from the tractor dealer and take it to the dealer close to home for service...if it ever needs other than routine service.
Don't let anyone tell you different, Stihl makes excellent equipment. The reason I bought RedMax was because I wanted to try something different after many years of running Stihl. RedMax seems to have a large following with lawn/landscape companies in this area.
And yes, the 45 minute drive would come into consideration. That's extra expense(time and fuel, etc.) to consider.
I have a Stihl HT101 telescoping pruner with the new Stihl 4-mix engine, like the engine's in the BR550 and BR600 blower's. It starts very easy with little pulling power required on the starter handle and runs very quiet. Also seems to have less vibration. It would be a nice addition to a backpack blower. Maybe I should have tried the new Stihl blower's before I purchased RedMax. ???
Curt