I haven't bothered to upgrade to the latest Firefox, so I am still using FF26. However, the "Directory Tiles" that they are talking about already exists in FF. It just doesn't work very well.
The "Directory Tiles" show up when you use the "New Tab" button. It is suppose to fill in over time with sites culled from the user's browsing history, frequently visited sites, and bookmarks. But I have never seen more than two of the boxes filled in. Maybe that's why they are putting sponsored web sites there. The sponsored sites will just fill in all the empty spaces.
I find that page a total waste of time and hope they give you an option to disable it.
I might be mistaken, but I believe you can disable or bypass the "tiles" by setting the homepage and new tab page to a different default page.
My thoughts exactly!
Google Chrome has been my go-to browser for quite some time. It's pretty nice to have all of my bookmarks and history synced between my work and home computers and my Nexus 5.
I primarily use Safari for Mac for similar reasons you listed but for syncing on my computer, iPad, and iPhone. I use Firefox as a backup for the few sites that don't work well on Safari.
I use Firefox on my work machines because it supports most sites. Internet Explorer is my backup and primary browser for Microsoft products like sharepoint, skydrive, office 365, etc.
Chrome/google have some cool features, but personally I am tired of giving google more information on me.