Not a waist of time or money, go for it. However from what I've read most prefer single coil.
I just started using a U-DCT mini double coil last night and even though it's early I'm really liking this
device, I'll upgrade in a few weeks to a bigger badder
tank, and single coil carto's.
If u want a good place for info as this is what I did, seek out Baditude here on ECF, he has blogs which help out immensely.