The GPU on my laptop is also upgradeable. And when I want to upgrade it, it'll be time for a new CPU too.
As it is now, very few GPUs in a laptop that can pull almost 200W and have 16GB of RAM. Mine is slower than the newest generations for speed but its quicker for long processing and large memory. When a 24GB GPU based on the 5x architecture comes out, I'll be ready with a new CPU too.