Me: Birdsite vs Here
I am there and here because people I want to follow are in both places. I was here before Wil Wheaton was persuaded off of the platform. I've been there since 2008.
I use the same client for both, I see both timelines co-mingled in post-date order.
Partly, I'm here because I believe in the overall mission of decentralized microblog services. Mostly, I'm here because I have friends that are much more comfortable here, where code of conduct is taken seriously.