Horrible choice for an American IPA in large amounts since it can mute hop character and muddle those bright citrusy aromas. It will give you more color, but that's of a minor importance to flavor.
With past experience at everywhere between the 4-10% range, I will never again go with Crystal 60 for my IPAs. 2% won't be harsh, but 8% will seriously diminish hop character in an IPA.
I usually go with 0% crystal, or as much as 5-6% Crystal 10, 15, 30, or 40.... or 3-5% honey malt.