FWIW, I got my EGO rear motor edger yesterday. Took it out of the box and slapped in a 2.5 ah battery that I had already charged and ready to go and tried out the edger. I've gotten pretty good at edging with a string trimmer. The edger's cut looks even that much better. Hopefully EGO will be releasing the tool only model soon so it will be more affordable for those who don't want another battery and charger.
I just picked up the edger for 129. using the battery that came with the other tools. 129 is not bad for a "multi" tool. Since the multi tool alone cost more than the tool with the edger. makes no sense. lol