ONE UI is available for manual flash on XDA. However, I personally do not recommend doing so, it is a good way to get the update with. Follow the link to learn how to do it manually and get the much awaited One UI https://www.youtube.com/watch?v=qd8a...
if you want best hardware it is samsung, if you want software it is One Plus always. However, i would recommend waiting for huawei's P30 and nubia x as well as meizu 16th and similar devices as well.
