Connecting 2015 15" Retina MacBook Pro to Dell U2715H? What would be the 'best' way to connect the 2015 Retina MacBook Pro to a Dell U2715H monitor? If I wanted to use the monitors USB 3.0 ports and also output sound to a Dell soundbar, how many cables would I need?

I was previously considering getting a Thunderbolt Display, but the reasons against are:


Bigger and heavier than the Dell
Ugly wide bezels 
Twice as expensive as the Dell 
Uses more power than the Dell


I do wonder what functionality I'll lose though. Will I end up having to (dis)connect HDMI, USB and audio each time I (un)dock the laptop?

Would I connect the MacBook to the display using some sort of adapter, or just the HDMI port? UPDATE: The U2715H doesn't support 2560x1440 over HDMI, only using the MiniDP connection.
Do NOT use the HDMI video output!

Please buy a Mini DisplayPort cable connect your MacBook and U2715H.