As soon as I write something claiming I'm using something, you can be sure that I will regret saying such five minutes later.
I'm still very (very) sure that I'm going with Pelican. But that bit about me using Semantic UI? No. No. No. Heck no. Not that there's anything wrong with it, but Semantic UI is not for me. At all. I spent the whole day yesterday digging into Semantic UI and learning about it, and when I figured it all out I got a flash of myself fighting with its design and class labeling every time I wanted to do something different from what the Semantic devs are doing. I don't think like them. That's really all I can say is wrong with Semantic UI. It's a nice package with lots of power under the hood with easy access. But it's not for me. I loved playing with Gulp, and Less and all sorts of things with Semantic UI, but I'm not a logical linguist master or whatever when it comes to thinking out css labels and such.
I'm playing with Pure now. No gulp, no Less, no fancy stuff at all. I miss 'em and could add it in either or both myself, but for now, going lightweight and being closer to the code feels more comfortable to me. I should have known to try out Pure earlier. I depended on YUI often before I stepped away from the web six years ago.