I usually run the GTi coils in the itanks 45-50 so that’s good for me. Single coil rdas I like around 40. My mtl tanks are usually 19-22.That's about where I have to run the Dead Rabbit 3 rta using the included coils which is a bit higher than I typically like but I haven't felt like changing them out yet.
I'm pretty content running 30-40 watts with most set ups though sometimes my single coil builds work in the mid to upper 20s which is fine.