If you have run, or know someone who has or does run a CO2 machine and can directly compare its performance and costs with a perc machine, please email me.  [email protected]

Here's my question, if you'd rather post here than email:

I see a lot of hype about these CO2 machines.  They're expensive (about $100k vs 60k for perc), but operating costs appear to be far cheaper and don't have the environmental issues that perc does.  What I want to know is, do they actually work?  I've heard from some people in the business that CO2 simply doesn't work very well, and that some people who go to CO2 have to revert back to perc to do the job.  

Looking for first hand experiences please.

Thanks!!