So far it seems like I will get my ROI well within a year (if BTC prices remain stable). Here is the balance growth chart (net earnings after fees, more about significant FEES further on):
Initial investment: 120 USD for 1 TH/s Sha-256, and 135 USD for 10 MH/s. I like how they break out revenue projections for you (although they don't appear to include mining fees - making the projections quite overstated). The last chart shows the fees, and based on this it seems Scrypt mining would have the better ROI. Another consideration is price of Bitcoin - on the one hand it raises the revenue, on the other hand, increased congestion from high BTC is contributing to the very high fees.
See here for mining fees for SHA-256 and Scrypt:
By my calculation fees are about 33% and 16% for each respective mining type. Definitely this makes ETH mining more attractive (however, the risk that it will move to Proof of Stake - replacing mining - creates uncertainty). On the plus side for Bitcoin, the investment does not expire (but profits get squeezed / ended if fees exceed mining revenues).
In short, this exercise taught me how contract mining works - including the significant role fees play. It also allowed me to purchase BTC (albeit it will take a few months to get my equivalent value back). For ETH mining there are no fees, but as mentioned, you only get a 1 year contract, and also there is an unknown risk that Ethereum will move away from mining. If there is any interest, I will post further progress, and also provide details on ETH project returns.
Good to all in their Crypto Quests!