At the moment I'm looking for a suitable laptop to work with Photoshop and Illustrator. The nVideoGeForce GTX series is mentioned in the system requirements as the recommended one. In the market there are many good models of laptops with a video adapter nVideoGeForce MX series. Is it worth considering such options?
It might be more useful to ask about specific models. Gaming laptops work well, as they have the right sort of spec, and have that economy of scale thing going for them. I like to use eBay to home in on a short list because of its filters. You can specify CPU, how much memory, make etc. and get down to a manageable short list of different models, and concentrate further research on that.
To answer your firs question, you can't go wrong with Nvidia GPU when it comes to Photoshop. Issues can arise with laptops which switch between onboard Intel HD graphics, to more powerful GPUs when needed. This is to keep battery use down, but you can force the laptop to use the more powerful GPU when plugged in to main power.
I have a laptop with nvidia 980m, and work very well with last Photoshop, not tested with Illustrator. Also , used one with 850m for 2 weeks and that was ok too.