Which is better Pandora hoặc iHeart Radio?

I've never had any kind of satalite radio but I want to know which is better and why. My Những người bạn say that Pandora but I like all the stuff that I've been hearing about iHeart Radio. So my câu hỏi is:
1.) Which is better and why?
2.) What's the difference between the two?
Thanx!