<font color=blue>That Ryobi does look like a nice unit but no way can it hack weeds like a gas powered tool.</font color=blue>
Why can't it? It has the same trimmer head, uses the same trimmer line and has more torque than the average gas powered trimmer in it's class. It uses all the same quick change attachments as the Ryobi gas units. I use the term "class" because I am comparing it to what the average homeowner uses, $125 units and lower, and not the high end units typically used for commercial landscaping/lawn service people. And of course it won't cut like your 6hp walk behind. But neither will the average $100 gas trimmer.
I probably wouldn't choose an electric for commercial use as well. But I also wouldn't choose about 90% of the gas units that the average homeowner uses for that purpose. None of the low end units will stand up well to extended day in and day out use. And the low end units, gas or electric, aren't designed to have brush cutters attached to them. You need to step up to the larger straight shaft units for that.
I have nearly 3 acres that I cut and then it takes me between 2 and 3 hours to trim along fence lines, drive way, rural road ditch and outbuildings. I've been doing all that with the Ryobi for 4 years and the only difference between it and the Sthil is that the Ryobi is lighter to carry, makes less noise, is easier to replace line and I don't have to mix fuel for it.
About 2 years ago I bought the cultivator attachment for it because I got tired of using the hoe in the garden. Best money I ever spent. It will flat dig some dirt. But my wife didn't like it because she thought it weighed too much. So about a month ago she came home with a Craftsman 49cc 2hp cultivator. It has wheels so she thought it would be easier to use. It has the exact same 10" tines that the cultivator head on my Ryobi has.
So how did they compare? The Ryobi beat the 2hp gas unit hands down. Digging dirt they both do the same except the gas unit tends to bog down occasionally. But I can get more done in a shorter time with the Ryobi. It hangs from my shoulder on a strap and I can move it from side to side as I go and I can slip it between plants as I go down a row. The Gas unit is on wheels and can only go straight. Go down, turn, go back, turn get between the plants IF it fits. Can't go sideways between plants with it.
I use my Stihl for light touch up when I have a little to do and am too lazy to get out the extension cord. I haven't even started my Poulan for about 4 years and not sure if it still runs or not. But, for the record, I also have a straight shaft 4 cycle Ryobi with a brush cutter blade on it. I got it last year when I had a place with a lot of brush and small trees I wanted to clear. The electric can't cut the brush and small trees.