I think Modern IE is great for touching operation. But the most issue is that the Favorites cannot be displayed by folders. Can you imagining that finding a website for 30 seconds???? So I use chrome all the time despite its bad touching operation.
I like the Modern UI IE browser because I often take the SPro as a tablet (no keyboard, mouse, etc.) but the simplified modern browser is not without it's weaknesses. I don't like that favorites cannot be in folders but I can work around that. The biggest issue for me is that I have not figured out how to save a webpage to disk without opening the desktop.