I am not beginning with an iphone model but with Samsung S9plus for sheer productivity and multitasking. Also Samsung's Note9. Then, as second, the Huawei P20 . Its Mate 10 is not far behind in powerfulness. It's the Chinese Huawei firm that are severely challenging the Apple brand and reliability is said to be good.
There's also Google's Pixel 2XL. However, most people will go for one of those above if not for an iphone. As for this, probably best to wait for the haptic touch system to be finalised rather than rushing out to get the i9XR.
When it comes to the most powerful smartphone that is out there today it would be a close battle between the iPhone X and Samsung Galaxy Note 8. It is these two smartphones that are the most talked about smartphones that are out on the market. The Samsung Galaxy Note 8 gets the slight nod for the world's fastest smartphone because it has a higher RAM capacity than the iPhone X. The Samsung Galaxy Note 8 is also lower in price and that is the reason that more and more people have been favoring the Galaxy Note 8 over the iPhone X. All in all though when comparing the processing speeds between these two mobile devices it is the Samsung Galaxy Note 8 that gets the distinction of being the fastest smartphone that is out on the market and for sale these days. Some forecasters are predicting that the success of the Galaxy Note 8 could be one big enough that Samsung could possibly take over Apple when it comes to the production of smartphones worldwide.