Given the inverse rule, a stable shot at 1/8 second not even including IBIS, there aren’t many compelling reasons for needing faster than f/4 on this UWA lens. Astro maybe, but nearly every other use case it’s not really there. You aren’t going for subject separation on 8mm, nor “bokeh balls”.
I have not yet ordered it but doing so is probably inevitable. Maybe you guys will say its crap and save me some money! I love the 10-12mm range on the 10-24 so pretty curious about this lens. I've heard some complaints about the f3.5 but I rarely have my 10-24 at f4 so I doubt it will be an issue. Although double duty as an Astro lens would have been nice.