We're not using it other than for internal failovers. We tried to build version two of our product on it. The costs increased rapidly until it was cheaper to buy a 42U and stuff it with HP kit and pay for a fat pipe. The storage was expensive, the per transaction costs are expensive, the bandwidth is expensive, the IaaS machines are expensive and the support is expensive when it goes wrong which it does occasionally and violently.
This was all financial data aggregation and archival stuff.
In test it was 23% more expensive than our own kit over 3 years.