awss:
I’m typing this post from the same exact machine you’re thinking of buying. There’s good news and bad news for you.
The good news is, the current versions of Unreal actually work pretty decently on it. MacBook Airs and lower-end MacBook Pros without a discrete GPU are a completely different experience, so disregard some of the comments above referring to MacBook Airs, because it’s not a comparable situation.
But, the bad news is that there is some truth in what people are saying. The Nvidia GT750, though it’s a good mobile GPU, is still a mobile GPU that prioritizes power consumption over processing power. Your machine will run hot, with the fan on most of the time you’re using UE4 unless you turn off most of the Viewport visuals (lighting, particles, etc.). You can also expect some fairly long build times. You will absolutely need to turn off GPU switching or make sure you only use it when plugged in, because the integrated GPU will just not cut it at all and, by default, it will kick you over to the discrete GPU when you’re running on battery.
Not knowing your situation, or knowing why you want a Mac, it’s hard to make a recommendation. I write Mac and iPhone software in addition to my work with UE4, which is why my principle laptop and desktop machines are Macs. If I hadn’t already had a fairly new, fairly maxed out Mac Pro when I started working with Unreal, I can’t say that I would have bough it for working with Unreal. If you’re going to be spending most of your time in Unreal, you can get a lot more processing power for your money right now by custom building a gaming PC than you can going with a Mac. If you need a Mac, you might even be better off buying an Air and using the difference in price between the Air and the MBP to build a gaming rig. Even a $1000 or $1500 gaming PC should be able to handle UE4 if designed right.
Another other issue is that UE4 really works best on a two monitor setup, and when you start driving a second monitor off that machine, your available GPU power is going to drop off substantially.
So, tl;dr version is, yes you can use it and it will function adequately if you turn off GPU switching or make sure you’re plugged in when using UE4, but expect fairly long build times. If you post why you selected a Mac and that particular Mac, we might be able to offer some additional guidance.