[NKCSS]

Semantic UI looks the best, but once you start to do your own things, you end up fighting it. I'd love to see some of the stuff Semantic UI does just as an add-in/theme for Bootstrap (Forms are beautifull).

I created an app for a customer in it, and while it looks shiny, it would have been more cost-effective to just have used bootstrap.

[afloatboat]

I've been helping out a developer that has been building sites with Semantic UI and it's making my skin crawl.

It seems like a good start for prototyping and admin interfaces, but for anything else it just adds too much styling and classes that need to be overridden.

The name seems poorly choosen, since you're constantly adding classes that reference styling decisions making it everything but semantic (ui very wide, ui very thin, ui three column doubling grid, …).