What do I choose? I want to purchase a 15" String Trimmer, but am confused by the types offered. The confusion is in regard to the drive train: rear motor vs. power head, or can I get an EGO battery backpack. What I really need is something lightweight. I have actually been waiting and hoping for an EGO battery backpack which connects with a cord to a lightweight, single straight shaft, 15" string trimmer. In addition, it would also connect to a hedge trimmer and other tools, thereby taking the weight of your wonderful battery off ones hands and arms. An English friend has an EGO Commercial version (BCX3800E and BAX1500) of such a tool. Surely, it is possible to market a consumer version in the USA, and soon. I will continue to wait and remain hopeful! -- By the way, I love my 21" SP Mower (LM2100SP), Snow Blower, Backpack Leaf Blower, handheld Leaf Blower (LB4800), and Hedge Trimmer (HT 2400, though it is too heavy).