What we really, really, really need is a breakdown on types of plastic.
All charts fail due to this alone.
If we can get an average player (about 350 ft drive), and the guts to pony out the money to mail him a disc to test and record, we can make a "comprehensive" chart. Better yet, if three people (250ft drive, 350, and 450) lived near each other we could make a beginner, average, advanced chart.
I'm sure we can cover just about every single plastic and disc out there with our resources. It would cost about $5 per disc (2.50 shipping each way).