All Windows PCs are pretty lame when it comes to OS and app support.
Apple if you are near enough to an Apple store will get you support on OS, most apps and the hardware.

Dell has been fine on hardware issues but if you have a software issue, they tend to have you factory reset the PC.

The two machines you picked couldn't be more different. The Air is nice but video editing would be a stretch due to onboard storage. 128GB is only for those with minimal needs for Word processing, spreadsheets, the web and such.

The Dell is your value gamer machine. Might edit videos faster but then you miss out on Apple's really great video editors.