I got an eGo One tank and a pack of CLR heads in yesterdays vapemail. It is really finely crafted compared to the GS tanks. A lovely brushed stainless finish that matches perfectly with the eGo One battery. The AFC is much more cleanly fitted than the somewhat sloppy fit of the M/MS. It has three tiny slits on each side which require excellent lighting at the perfect angle while carefully tipping the tank back and forth to ascertain whether or not you have juice in the tank without letting you tell how much. I am NOT a fan of this "feature".
It came with the 1ohm stock coil. Loads of vapor, a little harsher than my MS. Less than a day and the tank started gurgling, flooding, leaking, and producing a harsh flavor. So much for the stock coil, but I only bought it for the CLR heads. I've got one in it now, fine so far but I intend to rebuild one tomorrow at 1.4 or 1.5 ohm like I do for the GS before deciding its fate.
Based strictly on the stock coils, the GS beats the eGo One hands down on the eGo One bat. Even if the CLR heads kick ...., it's a hard choice. The GS are kind of cheesy looking in comparison, but man, they just work. My only problem with the GS is wrapping the coils on the rebuild. I build a perfectly functioning coil that tests out fine. Then I wrap it and put the cap back on and it dies or floods about 20% of the time.