A:Answer The newer GS65 Stealth laptop is thinner, and sports a non-gamer look for starters. Making it less obtrusive and more appealing to pull out in public. Next up there's a big difference in CPU power. The GS63 has a quad core 7th generation Intel i7 in it, whereas the GS65 boasts a newer 8th generation Intel i7, with six cores.
For productivity, I saw a youtube video from Dave2D which compared the two chips, and the 8th gen was able to finish a video render 5 minutes sooner than the other. The GS65 starts with a 1060 as opposed to the 1050ti, and the GS65 has 6GB of video RAM, which is much better than the GS63's 2GB.
The newer laptop is also considerably sleeker and lighter making it much more portable.
Bottom line, the 65 is a powerhouse and for 300$ of a difference, you are future proofing yourself with this device.