Here's the best analysis of the p2p storage niche I've read so far...
Analyzing Filecoin, Swarm, Storj, SAFE and Sia.

They expect Filecoin to grab an 80% market share in 12-18 months...
But feel there will lots of room for small players to thrive.

Swarm will have the huge advantage of full Ethereum intgration...
Storj has many user friendly features...
Sia has many unique design features including PoW, but usability is an afterthought...
SAFE is written off as "in perpetual R&D".

https://multicoin.capital/2017/09/27/state-decentralized-storage/