I have played with sia a bit. Can upload and download files to the cloud. I even set up a vpn to rent out some storage, but no one has used it yet. Renting space is still super cheap. Like not even close to profitable at this point. Hopefully adoption could improve that.
On the other hand at 20 satoshis they are inflating at around $1800 a day, and I don't know if that is sustainable. I think they would have been better served with a PoS variant. If they needed rng they could have used DPOS, and secured the network for much much less.
Their daemon and wallets are functional, but lacking lots of features. Documentation also seems to be rather sparse. I am a terrible day trader, so take this with a grain of salt, but I don't see their price going up with this low network hash rate and high inflation. Still really interesting technology. I'd love to see something like this built into BTS. Perhaps even a full fledged DPOS side chain.