I had the BR420 Magnum and liked it alot, only reason I sold it was for the BR600. Much quieter and alot more air volume. Not terribly much more air but definately a noticeable difference.

For those that you listed, I would go for the 550, but try the 600 also. I'm assuming you are like me when it's time to get the leaves cleaned up, don't make it an entire days work....especially if you have kids, the price difference justifies it in regards to leaf blowers.

Buy the most powerful you can afford and if $100 is in your way, take the jump. It's not like buying chainsaws...you can always go too big, not with blowers...more power means it's an easier and quicker job.

The BR600 is awesome.

I used to work for a Stihl dealer, we quit selling the BR550 because it was too close in price to the more powerful BR600. The Echo blowers are very good, I prefer 2 stroke over Stihl's 4-mix, but the PB755 is 4lb heavier.

2 cycles only. Maruyama BL8100 is even slightly lighter than BR600!!

Is the BR 600 more better than the PB-755? I saw a demonstration of the PB-755 to BR600. The power of the BR 600 was much more powerful than the PB755. I need something that can move leaves quick... this is what I need... haha.. someone had both a pull and + the BR600... incredible..

http://www.youtube.com/watch?v=Oa34ITLad18&feature=related