This Comet description is very accurate:
Comet changed the beer completely. VERY potent hop. Very grapefruity, and dank.. Extremely dank hop when dry hopped with it. Makes Columbus seem tame! Had a semi tart grapefruit and melon aroma and flavor, and maybe a little tangelo in there.
Here is my Heady Topper revision, which I have not yet brewed. Nevertheless, having used Comet in the past, I really think it is in there but only about 2 oz. worth per 5 gallon batch.
1.074 / 1.011
86.9% Pearl Malt
4.60% Corn Sugar or Turbinado
4.60% White Wheat
3.90% Caramalt
13-14 ml HopShot @ 90 Minutes (shoot for about 155-170 IBUs)
2.50 oz. Simcoe @ 160 F, 45 Minute Hopstand
1.00 oz. Centennial @ 160 F, 45 Minute Hopstand
0.75 oz. Columbus @ 160 F, 45 Minute Hopstand
0.75 oz. Comet @ 160 F, 45 Minute Hopstand
1.50 oz. Simcoe @ 8 day, Two-Stage Dry Hop
1.50 oz. Centennial @ 8 day, Two-Stage Dry Hop
1.50 oz. Columbus @ 8 day, Two-Stage Dry Hop
1.50 oz. Comet @ 8 day, Two-Stage Dry Hop
0.50 oz. Apollo @ 8 day, Two-Stage Dry Hop
Conan @ 63 F, then ramp up to 68-70 F after ferm slows down/completes.