They have a very similar sound signature, and are designed to hit the same sort of performance level. The G Pro is a little bit more sculpted, and the Cloud Alpha is a little more accurate to the original audio.
Look how closely they measured over at Rtings!
Headphones - 1.2 - Graph
Wireless Earbuds Wireless Bluetooth Noise Cancelling Running Earbuds And In-Ears Gaming Xbox One PS4 True Wireless…
I’d go with whichever one has the most appeal to you personally.
If you still want me to weigh in as though I were making the decision... I know I personally like to save money, so I’d lean towards the G Pro, which I also think has a nicer-sounding microphone by a hair.
It’s a bit clampy on the head initially compared to the Alpha, and the leatherette isn’t as soft, but I don’t know if those things are worth extra money to you, since I’m not inside your head. :)