Which L-mount zoom lens is gonna be the absolute best for my big trip to Japan next month? I just snagged a Lumix S5II and I'm honestly so hyped to use it but I'm completely stuck between two options for my main travel lens.

Right now I am torn between the Lumix 20-60mm and the Sigma 28-70mm f2.8. I love how wide that 20mm gets for all the shrines and narrow streets in Tokyo, plus it's basically weightless, but then I think about the Sigma having that constant f2.8 for night shots at the markets and I just dont know... I'm really trying to keep the kit under $900 and as light as possible because we are gonna be walking like 20k steps a day and I really dont want to be lugging a massive brick around my neck.

Is the extra width of the 20-60 worth losing the low light performance of the Sigma? Or is there some other zoom I totally missed that fits the budget? Just trying to make sure I don't regret my choice when I'm halfway across the world...