If you don't need color management, Viewnoir is much faster and lightweight. Geeqie, for me, was slower to open than Ubuntu's default Image Viewer and always showed that ugly "Geeqie" logo before it showed my image. And Geeqie is a weird and hard to pronounce name.
Viewnoir is much better for me.
I'd like to have Viewnior instead of shotwell. It's simple and lightweight and I usually don't need managing photos or gamma correction (I use GIMP for every types of editing).