JT - I really like Nelson in APA and AIPA, and to me it's grapefruit with a white grape juice character. Goes well with most American hops IMO. It's stronger than say Cascade, Centennial, or Amarillo for example. I love it 50/50 with Galaxy. As for amounts, it's obviously subjective. On APAs and AIPAs, I get my IBU from a 60 minute addition of Warrior (APA) or Columbus (AIPA) and late character from whirlpool and dry additions. These are the last 2 hop schedules I did with Nelson, both with Galaxy. Both were stellar.
APA - 40 IBU Warrior @ 60, 2.5 oz EACH Nelson and Galaxy in a 175F whirlpool/steep (30 mins). 1.5 oz EACH dry in 5 gallons. 1.055 OG.
AIPA - 65 IBU Columbus @ 60 mins, 4 oz EACH Nelson and Galaxy in a 175F whirlpool/steep (45 mins). 3 oz EACH dry. 1.062 OG.
Hope this helps some. It's great with Simcoe or Chinook 50/50 for some piney balance, or other fruity hops as well.