I've had my blower a few days now and put about 4 hours on it. It's certainly very powerful, very loud and very thirsty. It seems to be running a bit rich because it gives off fumes like my old Shindaiwa EB-630 units do. I'm not choking on it but it's noticeable.
Comfort is a bit of an issue for me. I can't seem to get it sitting on my back how I'd like it to and although the shoulder straps are curved they sit out further on my shoulders than is comfortable for me. This is where a sternum strap would help. Mind you I've done over 3,000 miles of long-distance backpacking and have been a professional landscaper since 2002, so I'm no stranger to carrying things on my back and no wimp. It doesn't feel heavy to me, I just can't help but keep trying to fuss with the adjustments on the straps and can never seem to get them right. The padding is good, the position of the unit on my back and shoulders just feels wrong.
I had to put the disc in to block the air flow against my back because temps are down in the 50s now and it blows quite a bit of air on your back. It even blows a substantial amount with the disc in. I'm sure it will be nice in the summer but so far I find it to be giving me an unnecessary chill.
The detent on the cruise control level between idle and off is basically non-existent on the tube throttle model. I've already shut it off by accident twice trying to idle it down and once while putting it on. The hip throttle model has a much more obvious detent.
The tube and handle also have comfort and use issues for me. The elbow and flex tube are so large in diameter that they hit my hip if I try to move it left much past the center of my body. The limit is around the 11 o'clock position so if you want to blow left you need to twist your body. I've messed with the angle of the handle and its position fore and aft and no matter how I adjust it my elbow keeps hitting the top of the flex tube, making it tender after a while.
The good news is that it reliably starts cold at 3 pulls and at 2 pulls when warm. It's ready to run almost immediately and throttle response is excellent. There's no noticeable vibration from it; the spring mounting system does an excellent job of isolating the machine from the frame. The tube is about the right length for me. It produces a wide and powerful stream of air that's good for moving leaves and bulky debris like twigs and light brush. I haven't had a chance to try it on large acorn accumulations, pine needles or pine cones yet. Scouring of stuck material is good but not excellent like some units with a higher air speed and more focused stream. Overall it seems to strike a pretty good balance of air flow and velocity and the power is impressive.
The cruise control is a bit tricky to get it set exactly where I want it and I wish the lever was a bit bigger. What I tend to do with tube mount units is to set the cruise at a good speed for what I'm doing and then use the trigger as kind of a turbo when I need some extra power. On this unit I tend to just use the trigger because it's hard to adjust the cruise control with just the small lever and if you hold the trigger and then slide the lever to where you want it, it backs off. Again, it seems like a constant fussing rather than just being how I want it, similar to the straps. I do like that you can hold the trigger all the way in and then slide the cruise control all the way past a locking detent so the throttle doesn't back off over time like it can on some units.
The bottom line is that although this blower is extremely powerful, I'm not in love with it the way I was with my Husqvarna 580 BTS and instead find it kind of annoying to use. The negatives are all pretty minor but add up to the point of annoyance to me. It shouldn't be hard to put a blower on, adjust the straps, operate a cruise control and move a tube a tube around. Maybe I'll get used to it and get things adjusted so that it's comfortable for me but if I haven't managed to do that after 4 hours of use I'm not very hopeful. I want something that I can just throw on my back and use for an hour or 2 without having to fuss with it...ya know. Maybe I won't care once the leaf piles start getting big and I get to use it to its full potential, but I can't see it replacing my 580 as my preferred blower for my mowing route at this point.
I'll put up some pictures and a video or 2 when I get a chance.