As a bit of background, I previously worked for the Poulan/WeedEater Division of Electrolux (and one of it's distributors) for nearly 30 years. They market and sell under various outdoor power equipment brands, including Poulan, Poulan Pro, Weed Eater, Partner, Pioneer, Husqvarna and private label products for others such as Sears/Craftsman. For many/most models the major differences are largely cosmetic to purposely distinquish between the brands & different sales channels, consisting of housing silouette design & color. Occasionally there also may be a bearing used somewhere instead of a bushing, etc. On many/most models of like displacement the core components of cylinder, piston, carburator, and ignition module are the same down to the part number. It is always gratifying to note that the marketing "works" when consumers (and even some dealers)say "brand X is better built, has better components or specs than brand Y". Some consumers (even retailers!) seem to think paying $179 retail instead of $119 for the "same" 2-cycle straight shaft trimmer (for example)of a different "family" brand/color automatically makes it "better". They will argue endlessly about it as well. I have been in the factory in Nashville, Arkansas and watched the various "family brands" come down the line and have the different brand housings assembled over the "same" base engine assemblies, by the same workers.
That being said - this particular trimmer is different, indeed. This one has a 4 stroke engine where mixing gas & oil is not required. It has an engine private labeled FOR Husqvarna and is not offered in some of the lower priced family brands.
Although I have used Poulan, Weed Eater or Partner branded 2-cycle products successfully for decades, I am now moving away from 2 cycle products where possible. The "awful" gasoline available these days includes ethanol which is extremely hard on the little rubber diaphrahms in the carb anyway. When you add mixing oil into the bargain with the gas and alcohol, the life of these little parts is further shortened. They lose their flexibility and the result is difficult starting and/or poor running after only a couple of years of use. This is why many state that they previously used older Weed Eaters for (several) years and now experience starting/running problems after only a year or two - the trimmers now are "junk". It's not the trimmer; it's the #$#@ fuel. Oh sure, you can purchase a carb rebuild ket for about $20 and invest the time and effort every second year to rebuild it yourself. If, however, you have to pay a repair shop to do it for you ... well ... it can easily cost more than a new price leader trimmer.
This is a great little engine that starts easily and runs well. I would have given it 5 stars for sure but I experienced the same darn issue with the shaft not being fully engaged with the engine and the head would not turn properly. It is pretty safe to say that unless you purchase this from a dealer who will assemble, service and test the unit before you buy it ... you are likely to have this problem.
As I purchased mine from Amazon, I did not want to go through the hassle of taking it to a service center and waiting for the "repair" to be performed under warranty. I loosened the four allen head screws (the tools are included!) and placed the engine assembly at the base of a tree and pushed the shaft assembly down into the motor housing and retightened the 4 allen screws. Of course, the engine started and ran perfectly. It has plenty of power for any "Weed Eating" need. Being a 4 cycle, it is a bit on the heavy side compared to the 2 cycle Weed Eater straight shaft units I have used in the past. Also, the head design works "OK" but seems to be a bit over engineered and offers no real advantage in use over the ages old Weed Eater tap-n-go version.
All in all, a good little trimmer to invest in for those that have a sizeable amount of trim work to do.