Are the dual and single coil cartos the same size or is the single coil a bit smaller. I bought the dual coils and I have only tried one but it really drained the battery on my ego. I liked it but I'm wondering if 1.5 is a little to low for my ego and if the 2.0 ohms would be better. I was really curious about the size of them and if they are a little bit smaller than the 1.5 duals.