Sigma 18-35mm f1.8 is sharp, and not too big. I'm pairing it with my GH5 and the Viltrox Speedbooster which makes this lens a f1.2, and thus is very suitable for low-light situations.
Thanks to the f1.2 and minimum focus distance, the bokeh on this lens becomes incredible.
I definitely recommend buying this lens.
Perfect lens! I also have a telephoto lens, however I keep coming back to this one as it feels more 'natural' on 25-35mm.
Can also get some great wide-shots in 18mm.