The display issue is really up to you -- if it's not acceptable, return the system for a refund (you have 30 days from the date of shipment if it was purchased direct from Dell). No gaming system can perform well on battery alone.  For anything but the least demanding games, you need to have the system plugged in.  That's not unique to this system or Alienware -- it's that the power consumption of the CPU, GPU and screen cannot be met by a battery alone;  you need AC power for anything more than very casual gaming.  
I just got my m17 R5, and while I love the screen size and overall performance of the machine, it has some terrible and very annoying backlight bleed. I contacted dell support via chat, and the guy I spoke to told me it's normal. After doing some research, it seems that a lot of people have the same issue with their m17 R5 as well. The second issue I'm having is regarding the performance on battery, the machine throttles the CPU back to under 1ghz when running on battery making the laptop so slow it lags playing back video It also causes the speakers to crackle. This is my first Alienware product, and I was really hoping for more from such a premium brand. Here are some photos I took at 80%brightness and 50% brightness, and a movie playing with the same 2 brightness levels. It is very annoying when the movie has black bars. [IMAGE][IMAGE][IMAGE][IMAGE]
m17 R5, backlight bleed, performance issue when running on battery