i've heard bisexual also implies being attracted to different genders in different ways whereas gender is completely irrelevant to pansexuals?
Well I'm bi, and gender doesn't factor into my attraction to someone. I can barely articulate how I'm attracted to one gender, let alone contrast that to my attraction to another, so that doesn't hold true for me either.
Basically, bisexuals are a very very big group. We're not all the same, and the one thing we all share that makes us a community is our attraction to two or more genders. Some people are attracted to each gender differently, or care about someone's gender presentation, or like certain things about certain genders, and others just don't.
I just like people, you know? It's incredibly hard for me to describe my sexuality in more specific terms than that, and I'm not about to start trying again.