Well you really have to ask yourself if you need mobility. Will this be for work that requires having a computer on hand at all times? If so, I would recommend going with a laptop...will this be for school where you may or may not need a laptop for use in the classroom? If so, I would recommend choosing the laptop.
From my perspective, Mobility is only necessary if you really need it. If you are only torn between mobility and power because mobility is more convenient, then I would choose power over mobility.
I say this because desktops have a lot more options. You can choose what you want to build your computer, and if you want to upgrade, you can upgrade at any time. I'm not saying upgrading a laptop is impossible, but it is much more difficult than upgrading a desktop computer. The graphics card in that laptop is a good one, but graphics cards in the world of technology become outdated very quickly. It's unfortunate but true, and as I stated before, it is much more difficult to upgrade a laptop than it is a desktop. Actually, I'm not sure that you can upgrade the GPU in a laptop.
Also, when gaming, laptops tend to generate a lot more heat, and heat is the death of electronics, whether that death be immediate or progressive. If you have a good case with plenty of potential places for fans...then desktops can provide plenty more ventilation and last longer than a laptop.
So, in summary, I would choose the laptop if it is absolutely necessary for work/school....however, if you believe it is not absolutely necessary and you just plan to use the computer for gaming or your own personal use...I would recommend a desktop without a doubt.
In the end, I believe this is a decision you will probably make on your own, but that is my opinion. If you have any questions or concerns, please feel free to ask.