There is finally a gamepad that solves the problem of Xbox and Nintendo controllers having reversed face buttons! It is called G4 Pro by GameSir and has a similar Xbox shape to the G4S controller but, instead of led face buttons, the GameSir G4 Pro has magnetic face buttons that you can swap around from ABXY (Xbox/PC) layout to BAXY (Nintendo) layout. 
You simply insert your finger nail and pull each face button and then reattach by slotting the button back in. There is no fiddling around, thanks to the small grove on the side of each face button, which prevents the buttons being inserted the wrong way around. The face buttons make an audible mechanical sound when pressed.
The GameSir G4 Pro Bluetooth gaming controller features an 800 mAh rechargeable battery that recharges via 5V/1A USB-C input, taking 2.5 hours to fully charge. Runtime is up to 30 hours with motor feedback and power button led set to low. To increase/decrease motor vibration, simply hold S + D-pad left or right navigation.

The run time is pretty good and, the GameSir G4 Pro is able to achieve it, thanks to two power saving modes, which automatically put the controller in sleep mode (while connected) within 10 minutes when not in use. When the game is powered on but not connected to a device, the G4 Pro controller will also go into sleep mode within 2 minutes. You can use the G4 Pro controller during charging too.
Like a lot of gaming controllers these days, the GameSir G4 Pro controller integrates a phone clamp capable of holding a smartphone at two viewing angles (120 degrees and 150 degrees). The clamp contraption is made of plastic and it's internally spring loaded so, you can fit different size phones (up to 8cm wide) and weights. The phone clamp angle adjustment is fairly secure so, it's strong enough to hold a weighty phone without collapsing. 
The GameSir G4 Pro controller buttons, including the triggers and bumper buttons are made of hard plastic. The analog joysticks are also made of hard plastic with a rubbery top surface for grip and have medium dead zones; hence the G4 Pro joystick deadzone is not too sensitive nor is it too unresponsive.

There is also a proper digital d-pad, which is always great to have on a controller for precision games like fighting since you don't have to move as much for directional inputs. Street Fighter is one of the few exceptions though, where using analog sticks is better because you have to frequently execute quarter circle and dragon punch motions.
The G4 Pro dpad is concave and cross-shaped, which allows the thumb to rest comfortably, although there is no center pivot, which gives the d-pad its precision. The center pivot also prevents you from accidentally pushing the d-pad down and press every direction at once. The GameSir G4 Pro controller is comfortable to grip with both hands, thanks to the textured rubbery material covering the outside perimeter of the handle grips. 

The GameSir G4 Pro controller has four tiny leds on the top left side of the controller to indicate battery status in 25% increments. When the battery is below 15% level, the last led will flash quickly. 

The GameSir G4 Pro controller can be used three ways: 1)Via Bluetooth, 2) Via 2.4Ghz dongle and 3) Via wired connection. The 2.4Ghz wireless dongle is included with the GameSir G4 Pro and stores safely inside the controller so, you don't lose it or misplace it. 
The GameSir G4 Pro controller supports Android controller supported games from Google Play Store, as well as Apple Arcade and Mfi games from the App Store. 

Not all Apple Arcade games with controller support are listed as such (i.e. Exit the Gungeon, Bleak Sword and Cardpocalypse); while some Arcade games have the official controller support badge at the top of the game page, which makes it more convenient than having to go looking in the description of the game. 

For fighting games specifically, it is best having a d-pad with separate buttons so, you don't accidentally press buttons at the perfectly wrong time! Being wireless, you can expect the usual input lag with the G4 Pro. If lag is an issue to you and prefer gaming controllers with split d-pad check out the review of the X2 telescopic controller.
Aside from controlling the in-game action, you can also control the intensity of the dual motor vibration feedback (rumble function), as well as control some phone functions, including screenshot, volume and mouse cursor (X+select). 

There is also a Turbo mode to create a one button macro sequence so, you can have a particular button activate on and off really quickly. If you like playing VR racing/flying games, you will be glad to know the GameSir G4 Pro integrates a 6-axis gyroscope sensor that works just like the gyroscope function in a phone so, you can steer without using the dpad or joysticks. 
The GameSir G4 Pro weighs 254 grams and measures 16cm long, 11cm wide and 6.3cm high (including joysticks). 

A Gamesir-branded USB-A to USB-C charging cable measuring 80cm long is included, along with a plastic adapter for increasing the width of the clamp holder so, you can accommodate thicker phones and/or phone cases. You can buy the GameSir G4 Pro on amazon and you can also check out more GameSir controller reviews bellow: