I'm in the planning stages for a simple twitter like web app. I want to use a Baas to make life as simple as possible. I've narrowed the options down to...

www.parse.com
www.firebase.com
www.kinvey.com

I know they all have their strengths and weaknesses but what it would be great to know from anyone who has experience in building these kinds of apps, is which service would suit a real time twitter like service the best?