Thanks for the interest in ScopeFans.com! The idea is to give guys like ving an easy option. You could easily make a fan for less money in materials. If you value your time at all, I think you'll save money by going with a ScopeFan. I've already done the engineering and assembly work!
On my personal Newt, I've found that stable planetary images can be had after only 20 minutes of cooling with the fan installed. This is after taking the telescope from indoor temps of ~25C to outdoor temps of ~-10C. That's just not possible without a fan.
Regarding vibration isolation, my testing shows that there is no discernible vibration present with the fan speed lowered to its minimum setting.
Thanks,
Pat Dotson
www.ScopeFans.com