Great site and great initiative. Hopefully there will be thousands of reviews there some time soon
I want to offer my opinions on what could be done differently. You should completely remove the "isolation score" for open phones. I am currently looking at the Alessandro MS2 reviews at your (great) site, and the total average suffers from a 1.5 isolation score. For some reason the SR225's have received a 3.5 isolation score...
Likewise, the DT880's get a 1.5 portability score while the ATH-L3000 is far more portable with it's 3.5 average.
Note: I didn't calculate the scores to check if the "closed" score were in on the total score, I just assume it is
It's not easy getting correct, or rather coherent, results when different people review different headphones, as we all know. So, what can be done to remedy this? The average scores might be presented differently. Each phone could have an "audio quality" score, a "portable use" score, a "home use" score and an optional "closed phone" score which would be "audio quality + isolation" that is only displayed for the closed ones.
Also, it might be easier for both reader and reviewer if there were fewer properties to rate. Do people really know the differece between bass impact and extesion or interpret it the same way? I think fewer options might result in more coherent results. You will be trading some detailed info for hopefully more correct info. I am sure you have thoght about what properties you wanted to include, and no matter what you chose, someone will always have complaints about the selection.
I am not saying that my suggestions are the better solution, I just want to offer my thougts for you to concider.