TL;DR: Gridcoin > SONM/iEX/Golem!
Gridcoin is a cryptocurrency which securely rewards volunteer distributed computation (such as attempting to cure diseases, Protein Folding, mapping the milkyway, searching for extraterrestrial life, detecting/analyzing asteroids, etc) performed through BOINC projects on top of proof of stake.
Unlike Golem/iEX/SONM you can distribute literally any kind of distributed computation and the Gridcoin network will pay your volunteers on your behalf where as you have to pay up front for limited computation on Golem/iEX/SONM. Think about the fact that anyone can create a cloud service where computing power materializes from volunteer participation and your volunteers/workers have their electricity bills offset by a third party. Why bother paying for computation when you can effectively get it for free?
Got a good idea which requires 100k+ CPUs? Post it to the project brainstorming thread! Feel free to run with any of the discussed ideas!
The Gridcoin network rewards 2k active users, has 9k members, 110k+ hosts, yet represents approx 0.5% of the active BOINC userbase. Once we remove the team requirement we face potentially scaling from 2k active to up to 500k active & 4 million registered users. For a proof of stake crypto (which requires a positive balance to earn BOINC earnings) this makes Gridcoin look worthwhile holding for the long term (not financial advice).
What Golem/iEX/SONM do better than Gridcoin is focusing on establishing a direct 'crypto:computation' market. Anybody can potentially come forwards with token and direct computation power to a compatible task they desire completed where as with Gridcoin rewards are distributed to the volunteers of a BOINC project without the project administrators having to pay.
A 'GRC:Computation' market could potentially be built into a Gridcoin pool (open-source kit WIP), or perhaps directly into the Gridcoin reward mechanism through a proof-of-burn system (directing more rewards to project A over project B proportional to GRC burnt against project burn addresses) or directly within a commercial BOINC project.
It's a reality that GRC has distributed its tokens against verified BOINC computation without a premine/instantmine nor ICO, where as iEX/SONM/Golem all performed ICOs upon the ETH platform. By raising millions through an ICO you have that large initial marketcap & you have a lot of money to hire marketing experts; raising a large amount of money through an ICO isn't a sign of a successful project though (note that none have any deliverable in production yet? It's all speculative).
There's no proven compute capacity behind iEX/SONM/Golem as all asset holders are investors, where as GRC was distributed to individuals with proven computing power.
Visit the #Gridcoin SubSteemit!