compared to XLR-18, ui-24, dl-1608, etc it is large. But it is a control surface. So really a different class of beast. Sized like a Presonus 16.4.2 - except that it is far more capable. .. and the sound quality is a major step above the pro-sumer level stuff.
If the Soundcraft ui-24 had MADI and would have integrated into my sound company rig, I would have done that instead as I am comfortable mixing from glass, like the small form factor... overall the si-1 made more sense from an integration standpoint.
I may audition one of the ui mixers from Soundcraft. A Ui-16 would meet my needs in a personal mixer and I like that little lunch pail format of the ui and XLR series boxes. If they carry similar sound quality my dl-1608 will be on the chopping block.