I purchased the G7 - 7700 and it is a very good laptop and a bargain for the hardware it has installed. Have not experienced any cooling issues - at max GPU load it does get warm, but consistently stays well under 80 degrees C. I did take the time to download and install several updates to the machine including a bios update. I also purchased the Cooler Master NotePal U3 PLUS - Gaming Laptop Cooling Pad with 3 Moveable High Performance Fans (Black) to help with any heating issues - but really it hasn't been needed yet.
The issues I have had with the machine -
1) Delivery was delayed 2 weeks due to an apparent Killer Wi-Fi parts shortage
2) The RGB lighting config software from Alienware is pretty obtuse - flickered badly in one game, so ended up just disabling completely because I run an external monitor, SteelSeries keyboard, and mouse anyway. An issue to be resolved in the future if I ever need to go more portable with it. Right now it's more of a desktop replacement box.
3) Could use an extra USB port on either side.
It is a hefty laptop - 7 lbs, but with a beautiful, bright, and responsive screen - see no lags or tears in any games. Power brick is pretty big too.
Killer Wi-Fi is just amazingly fast.
GPU Nvidia 2070 super has effectively tripled FPS rates in most games I play - much sharper details, fan noise not noticeable.
Even the cheap Realtek audio onboard does not sound too bad.
This laptop is a real win/win - don't think you'll find a gaming laptop with better hardware installed for the price ($2089) and I looked pretty hard.