Sia piqued my interest too. However I made the mistake of buying my initial Siacoin on Poloniex which instantly lost them when I tried to withdraw to my Sia wallet. I'm not the only one to lose Siacoin either. There's a very busy channel on Sia's support Slack dedicated to Poloniex's lost transfers.

UPDATE: It looks like the issue was at Sia's end of the transaction. This blog post https://blog.sia.tech/growing-pains-8e7b01c56f7e explains what was happening. Here's hoping they can stabilise this quickly.