First, a couple of tips regarding model and battery selection: Unless you are someone who ultimately just needs to have the most powerful offering available, or believes that your equipment has two speed settings (on and off), then save yourself a little money and give the 615 model serious consideration. Under normal use, you won't be using either model at anywhere near their full power settings, except for maybe one or two brief shots. If this will be an addition to other Ego tools that you own, consider the 2.5Ah battery. The battery comprises roughly half of the weight or more for the tool in its usable state. The 2.5Ah battery charges up in 20 minutes on a rapid charger, and if you need to continue working instead of taking a short break, a larger battery such as the 7.5Ah from a lawn mower will easily let you continue while the small battery is recharging. Your arm will definitely let you know about the additional weight of the larger battery, though. The 2.5Ah is about the right size for runtime on a typical work/break interval, but very likely will not get you through a typical yard clean-up job on one charge. Ideally a pair of 2.5Ah would be a good solution for near-continuous use (one charging, one on the tool) and still keeping the tool at a lighter overall weight. Yet, the batteries are the largest cost in this system, so using one from another tool when going non-stop is an acceptable compromise. If this is your first Ego product, then yes, seriously consider the 5Ah battery with the rapid charger. Just be mindful that the tool will be roughly a couple pounds heavier in use. As for the blower, well, it blows...well even. I usually turned the "cruise control" knob to a low to moderate setting and squeezed the variable speed trigger to increase the speed when working a larger cluster or stubborn leaves in a taller patch of grass. When working a developed pile, just turn the speed up or use the trigger more. I rarely found myself ever using the "turbo" button on top, which provides the tool's maximum power. This is the reason for my model recommendations above, though I also recognize that everyone's needs are a little different. Design-wise, the tool feels the most balanced in your hand with the smaller battery, though putting a 7.5Ah battery doesn't necessarily feel awkward, just heavier. An eyelet for an optional shoulder strap might be a nice design consideration for the next generation. For storage, there is a teardrop screw/bolt book on the bottom side for hanging up the tool. It's in a spot that can be a little hard to find when hanging since it's on the bottom and not readily visible. The tool hangs well with the battery installed, but maybe a little more precariously without the battery as the center of gravity changes significantly (again, the battery is roughly half of the weight of the tool). I'd recommend to Ego to include a basic snap bracket that secures the barrel while in storage to provide a more secure two-point wall mount. I was concerned reading a number of review of premature failures. I've used mine for several hours thus far without issue. While there certainly could be a design weakness, I also suspect that there are a few users that run the tool full-out for the entire capacity of the battery. The motor and the MOSFET electronics probably run pretty hot at high speed, and rely upon the blower to provide some level of cooling for both. If using at a higher speed for longer periods of time, it probably would be prudent to run the tool at a low speed for a minute or so before turning it off completely to help cool down the motor and electronics. Overall, it's another solid offering from Ego, a great way to cut the cord from an electric and an even better way to avoid another piece of gas power equipment that normally would see very seasonal/sporadic use and suffer from the problems with that usage pattern.
