I've been lurking here for the past couple of days, kinda new to high end headphones and need some advise. I have been looking at 3 different headphones. 1. Sennheiser HD 598, 2. Grado SR 225i, and the Audio Technica ATH M50S/LE. I don't have an amp yet but will be getting one very soon, I use an iPad, iPhone, and the new iPod nano for music. I listen to mainly alternative like Imagine Dragon, Mumford and sons, I also listen to Kings of Leon. I also listen to hip/hop and R&B. Just looking for some advise on these 3, I'm leaning towards the Sennheisers.