You can try using the 0.5ohm coil for the Cubis. Personally, I found it didn't work and just gurgled and gurgled away - the pure 'milkshake vape' took hold.
Over the months, I tried the complete collection of available coils. In the end, the 0.6 ohm proved to be the least unreliable and makes nice vape at 12-18 watts and actually that tank and coil is my daily work tank. I have 8 boxes of 0.6ohm coils for the UK vapocalypse.
(8 x 5 = 40, so almost one year's supply).
If I want to subohm and not use an RDA or RDTA, then I use Eleaf tanks (or the Aspire Evo tank 4ml) with the Eleaf EC heads.
At the moment, I am considering long-term use of a Joyetech Penguin when my Eleaf coils run out.
(4 x 5 = 20, so only a few months supply on two tanks).