n=1 on this but I tried it a few times with Chock Full O Nuts Dark New York roast and it made me excessively jittery. I then went out and splurged on some Wet Processed high quality coffee from Gimme Coffee! (a local roaster) and noticed a huge difference in the jitters and mental fog that sometimes comes with too much coffee for me too much at once. I haven't tried the brand that he is selling, but I can confirm that using better coffee gave me better results.