Overall, if I am correct. CoinTerra's upcoming new technology and Cex.io cloud hashing is not worth it. Simply put, you won't break even.
Assuming the price of BTC stays where it is. Which it won't. It's at $224 on BTC-E at the moment. I'm pretty sure a few weeks ago it was down around $110.
If BTC is $1000 this time next year, mining will still be profitable.
You buy cex.io shares for BTC, they pay out in BTC. How exactly the the BTC/USD exchange rate important?
You're repeating the same "but I made a profit in USD" fallacy that has been circling these areas for ages. If I just buy and hold BTC, I also profit in USD if the BTC/USD exchange rate goes up. If I spend $10000 buying BTC and $10000 buying mining stuff, at the end of the road the BTC-purchase will have performed better. And since buying and holding BTC is significantly less effort and risk than buying and operating mining equipment (even through hosted services such as cex.io), there is no reason to pick the inferior investment of mining over the superior investment of buying and holding BTC.