I don't do a lot of drip, so I don;t know the answer to this.

I had an interesting discussion with the Josh of CCC at our last get together, since he favors the Clever Dripper like I do for its combo of full immersion brewing and the subsequent filtration and clear brew. I expressed frustration since it took me about 2 minutes for the drip part, and I would prefer a minute or less. He uses a coarser grind that is standard, stirs for minute, steeps for two and drips for one. The steep and drip part use a lid. I'll be trying his recipe this week.

The industrial coffee companies have made a science of over-extraction. The most info is in Sivetz Coffee Technology. Especially the long section on making soluble coffees. The actual water solubles in coffee are 20% to 22%, the optimal extraction range. Everything more is breakdown products from hydrolization.

Modern instant coffee has a "solubles yield" of about 55% (up from the 45% in Sivetz's day, this according to Vizthum and Clarke). This miracle is achieved by brewing the coffee under pressure, at around 150C (20 bars!), for about 6 hours (down from the 48 in Sivetz's day). Fortunately, the really bad tasting stuff apparently is the 22% to 27% yield fraction. After that, it's all tasteless starch from broken down cellulose. So the taste of instant is like that of an amerciano made from the world's worst ultra-ristretto, that has also been left standing long enough to lose all its aroma.