As of now, I most likely would rather wait for Phone (3) or buy the 2a as some sort of inbetween device to get a feeling for Nothing. Since the regular iPhones are essentially expensive flagship devices, with great cameras, great build quality, good displays and so on, it should be mentioned the 2a and 2a Plus are mid-range phones at best.
The Phone (2) on the other hand, while offering good build quality, decent display, wireless charging and great performance thanks to that Snapdragon, it has a number of small quirks which can be very annoying. The vibration and haptic feedback for example is not only very weak since a number of updates, you also can’t adjust the strength and using custom tones doesn’t vibrate at all since OS 2.6
Additionally even the Phone (2) can have pretty good camera quality, it tends to be quite inconsistent in my opinion, with some shots clearly suffering from extensive image processing like oversharpening. Never owned an iPhone myself, but from what I’ve heard the quality of the camera is consistent and very good.