I love Amarillo hops. I also really enjoy the Amarillo and Simcoe blend. I think both have a great flavor profile, and amarillo in particular can be citrusy in some beers, but with the right grain bill behind it, it can come off almost pineapple like. It also has a low co-humulone level, so the bitterness you get from it is not harsh or bracing, but its almost soft even in higher amounts. It's just a great hop. Simcoe, can at times be almost soapy in high amounts, but in a blend, really offers some good hop bite and for some reason pairs real well in Amarillo. But, if given a reason to pick just one, I would go with Amarillo. Also, for the record, I brew mostly Amercian styles so the Amarillo hops go very well with most of those styles, maybe not so much the American stout, but the rest its pretty much perfect for in my opinion.