Nano is great tech. But also now Bitcoin is geting faster with Segwit being implemented by Coinbase and GDAX.
Combine that with Lightning Network rolling out soon too. Also Bitcoin Core's next version will have Seqwit by default too.
But hey, Nano's interesting too.
The biggest problem is fees, fees will always be an issue no matter how fast BTC gets. So NANO will always have that advantage.