Slow blockchain.
High prices (data from https://siastats.info/storage_pricing.html)
5.6$ for TB/Month, instead of 1$ like described on their website
When you download it you need to wait for the chain to sync, it takes 3 hours with high speed connection.
Consumes 10GB storage, make it unusable for phones
There is a danger to lose all hosted data, if you were online for more than few months.
It is sooo slow, it didn't started to upload my file after 20 minutes already.
And it took me about 5 hours to get this 20+ contracts to host my files.
For current price, I don't think it worth using...
The big catch with Sia is, that when price of Sia going up - it start to loose to amazon/google etc (only advantage is decentralization).
But when the price is low, it doesn't worth that match to store the data...
Project very immature, yet I must say the idea is amazing!
I hope it will get better, today I'm probably won't going to continue to use it after my contract is over.
Do you use Sia?