I've gone ahead and purchased a subscription to OnyakTech, and downloaded H2O.
Creating the form worked pretty well, there seems to be a lot of potential for this module but my opinion is that it is not ready for prime time.
The problem is the lack of useful documentation. The only documents that I've been able to find contain mostly descriptions of what the module can do but not much about how to do it.
There are also some issues with browser compatibility, error logging and timely response to support requests.
Under FireFox the form layout falls apart, for example the submit button rides in the middle of the form and the form blows out the bottom of any container you may be using. I'm sure I could fix this via the CSS files but I would hope that the basic install would work or at least be tested under multiple browsers.
When the module throws an error is displays a "friendly" error message on the screen but nothing is logged. I suspect that the event logging functionality of DNN isn't used. This makes trouble shooting very difficult.
I really want to make this module work for my site so if I'm missing soemthing obvious or there is more documentation that I'm not aware of I would be grateful if someone could point it out to me.
Thanks
John