Ehhh $350 for a 4K display sounds sus, a shitty 4K still costs more than an excellent 1440. For 4K the best ones generally are the ROG ones (also technically Asus), and if you're going with a 9070 then you don't need G-Sync just FreeSync support.
I would say if you can tank the cost for a 4K at the price point of the ROG options then go for it, otherwise go 1440. I use a *lot* of displays in my day-to-day and every single one of the 4K displays that are <$1k are shit. That's why I still happily use a 1440 at home.