I was faced with a similar situation last year and I ended up going with the 580BTS over the 570BTS, but I don't think you can go wrong with either one. The main reason I went with the 580 over the 570 was the simple fact that I already own a Stihl BR600 and to me the difference between the 570BTS and the BR600 was not as significant as the difference between the 580BTS and the BR600. There are advantages to buying the 570BTS though, 1) it weighs less, by about 2.5 lbs, 2) it's cheaper by about $80, and 3) it offers more mph, which is better for scouring wet leaves and other stubborn debris. Advantages for the 580BTS are 1) it and it's Redmax sibling(EBZ8500-Redmax actually makes the blowers for Husqvarna) are hands down the most powerful backpack blowers on the market, 2) I like the waist belt that is included on the 580BTS, I think it definitely helps distribute the weight more evenly and makes it alot more comfortable to use for extended periods of time(the 570BTS doesn't have a waist belt, just a padded waist area), and 3) CFM's, CFM's and more CFM's this thing will really move the leaves. In the end, I really don't think you could go wrong with either choice, and if I didn't already have a Stihl BR600 my choice might have been a little different. Also keep an eye out on Husqvarna's website, they usually run a promotion around this time of the year and I got a rebate of I think $35 back from them when I bought my 580 and IIRC the rebate was on their entire line of backpack blowers, and if you would like to do some more reading/research before purchase, just check out some of the lawn care forums on the internet(Lawnsite is a good one), like you I posted on here and got very few responses, but then again this sites mainly for chainsaws and wood enthusiasts and it's great for that. Just a side note if you're worried about the scouring-570BTS vs cfm/volume-580BTS, I got my dealer to throw in the narrower tube end from the 570BTS, so I have both the flared nozzle that comes standard with the 580BTS-great for spreading out the air flow for moving large volumes of leaves and the narrow nozzle(comes standard with the 570BTS) which helps increase the scouring/mph power for removing stubborn debris-both fit and they are interchangeable. I hope this helps and good luck with your decision.