Hi. I'm in a similar situation. Although, I have the chance to pick up a "refurbished" Skylake based XPS 15 (9550) for around 2/3 of new price, so this make the hardware around 65% less than the price of the similar spec refurbished MacBook Pro from Apple. My other big concern is RAM, as Apple are artificially limiting their hardware to 16GB, and I like my 32GB for additional VMs. That, combined with the 100% Adobe RGB 4K screen, means the Dell is MASSIVELY better value. The cheap price comes via auction, so if I win (I've set myself hard spend limits) then I'll let you know in around a week's time how I'm traveling.
Seems like most of the hardware works pretty well out of the box. Ironically, VT-d must be disabled for the install to work, so I'll be interested to see how much that affects my VM speeds (anyone know?)