With 2 AA batteries (included) you can get 40 hours of on-time before you need new batteries. The SteelSeries Stratus XL is known for its good battery life.
This is a full sized controller, and feels similar to the Xbox controllers. Its curves help it fit comfortably in your hand, and the controller doesn't become uncomfortable to hold even for extended periods of time.
If you have gotten used to an Xbox controller, the Steelseries Stratus XL is an amazing option. You cannot look at the controller while playing in VR, so being used to the layout is a huge advantage.
The 4 dots in the bar near the top of the controller are 4 LED lights which give you pairing information, as well as indicate battery life. They can be activated by pressing the battery button on the top of the controller (between the bumpers).
The joysticks are indented on top, giving your thumb extra grip. The texture is also grippy, making the grip that much better. In addition, these joysticks can be pushed in like on console controllers which acts like an additional button.
In the controller's battery door is a micro USB port, which can be used to power the controller without batteries (phone must be USB OTG compatible and you will need to USB OTG adapter). This doesn't work with the Gear VR's charging port however.
In order to use this controller with VR, you will need to use batteries in it.
Instead of an incorporated battery which can be recharged via a cable, this controller uses disposable batteries. You'll need to keep some on hand, and this will add to the overall cost over a length of time instead of simply being able to recharge the controller.
Unlike many of the other controllers mentioned here, this one doesn't fold, and it isn't flat so it can't easily fit into a pocket. You'll need a purse, murse, backpack or satchel to carry it around which makes this a less attractive option if you'll be gaming on the go.
The MOGA Pro Power is a full sized controller, just like a PS3 or XBox gamepad. Most Android controllers are smaller, which makes them more cramped and uncomfortable for longer use. A larger controller fits your hands better, making it more comfortable. Since you can place your phone on the unfoldable arm, it helps balance the phone's weight better so it isn't as top-heavy.
There is an internal 2200mah battery that can be charged through USB. You won't need to worry about having batteries on hand, or have the added cost of purchasing batteries for the controller.
Users have reported that the controller sometimes disconnects when other bluetooth devices are active at the same time, or when playing for extended periods of time.
The older model of the MOGA Pro had rubber grips in the back, sadly they have been removed from the MOGA Pro Power controller. This makes the controller a bit more slippery.
The internal 2200mah battery of the MOGA Pro Power is capable of charging your phone via USB while playing. This will reduce the battery life of the controller, however it's a convenient option to have when gaming on the go.
The controller feels solid with great build quality. It doesn't creak, and they are durable enough to last a few years at least. As a brand-name controller, they have a reputation to uphold and they certainly do that.
Though the controller feels light, it's solid and very comfortable to hold, especially compared to many other portable controllers.
The buttons on the controller feel clicky and the layout is similar to those of console controllers, making it intuitive to use. This is often not the case for portable controllers.
The Samsung Gear VR set is portable. If you want to use it on the go, you need a portable controller. The Moga Pro Power is relatively small and can fit in your bag without taking up a lot of space. The buttons and joysticks almost don't stand out from the case and it has short palm grips.
The 1800 mAh battery charges your phone with 500 mAh output. If you're playing with a powerful flagship phone, the controller will just slow down the process of discharging.
As a sidenote, the controller can charge your phone only if it has at least 25% battery left.
The controller has issues using the batteries. For example some users experience a problem where the controller uses only half of the batteries and then requires new ones. The controller doesn't have an on-off button either, so the batteries drain fast.