I ordered two for my business recently. I chose the Intel AC 7260 network adapter, which turns out to have all kinds of problems connecting reliably to 802.11n networks (the vast majority). On my laptop specifically, the motherboard and/or video card had major problems resulting in failure to shut down, an endless cycle of video adapter driver crashes and re-initializations resulting in system lockup, problems waking up from sleep, etc. I returned mine for a replacement, only to find the keyboard was absolutely horrendous--keys would double-press (bounce) almost every other key when typing fast and with moderate to heavy pressure. Upgrading the BIOS did not help as it apparently did with other Dell models.
Also, Dell refuses to refund my money on the now two defective laptops because I'm outside of the 30 day refund window. They wouldn't make an exception. I told them I was never purchasing a Dell again. I can (and did) buy a 2014 MacBook Pro with better specs for the same price and now I'm running Windows in Boot Camp (for .NET development) with flawless performance. Combined with a 3-year Apple Care agreement, I never have to worry about being nickeled-and-dimed over way-too-short refund periods.
In short, avoid Dell. They are shipping substandard hardware and are even getting things that should be commoditized to perfection (the keyboard) wrong.