I've checked out their investment calculator, but guess one can only estimate the returns. As there are a number of factors one has to consider such as BTC market value, increase in RoD, luck on the blocks, fees etc. Going by the payouts made in the last 24hrs, it's well above what the calculator throws up. So far so good.

Besides not sure if anyone just got an email:

Theere are some updates and the extended downtime and new fees they'd be charging 8th Nov on:

Excerts from the email -:
"Today, we had a hardware failure at our main backend server, which was beyond our control. We are going to replace the faulty DIMM memory module, which may take up to 5-10 minutes planned downtime to ensure that it will not happen again. However, all mining power will be compensated."

And..

"The maintenance fee:

The fee will be implemented in 1 week, which makes it November 8th 2013.

The maintenance fee is estimated as $0.30 / kW*hour:
$0.17/kW electricity cost + $0.09 data centre upkeep + $0.04 hardware repair/maintenance.

(The power consumption of 1 GHS is 1.5W per hour)

The fee will be billed in BTC per mining share. The estimated fee is 0.000000002695 BTC/share, which makes it ~4% of total mining profit. The fee will be adjusted according to the BTC/USD exchange rate.

About the hardware maintenance:
We will charge $0.09 for the data centre upkeep + $0.04 for hardware repair/maintenance.

Handling 600+ kW mining equipment is quite challenging. This involves MANY people working at the backend, who:
- Replace dead chips
- Fix PCB issues
- Upgrade electricity links
- Improve mining software to reduce stale shares (we have stopped delivering stale shares for purchased GHS)."