I love the Blackmagic ATEM products. As far as latency, any production switcher that has frame synchronizers will give you latency. You have to genlock all your sources to minimize this.
As far as titles, I would go with the SimpleSupers.com app. This let’s you use PowerPoint as a character generator with key and fill. It generates an alpha channel. You can use it with any production switcher that accepts key and fill. No need for green or blue screens behind your slides.
If your design/animations are good, no one knows its PowerPoint. Plus you can even use it to play out videos. And you’re already set up for the large base of PowerPoint users out there. (Of course you may have to re-format their presentations to 16:9, ugh.)
I use it every week at our church. PowerPoint plays out our intro video, then I key up Lower Thirds with peoples names, worship songs, scripture, etc using DSK 1 on the ATEM Production Studio 4k (all inputs are 1080i59.94). The DSK fill is my Laptop Display 2, and the DSK key is my Laptop Display 3.
Cheers,
kc