I don't want to turn this into a long post, so I will avoid unnecessary details. The short version is that I bought one of the new 5k Mac's with the Thunderbolt 3 ports back over a month ago. Overall it works great, but it does have some very odd compatibility issues with certain TB3 devices that work perfect on my MacBook (late 2016 w/touch bar). I have talked to multiple Apple Care agents, senior agents, ones that work data gathering, etc... The end result, weeks and weeks of Apple calling me directly asking me to screen share, plug in the devices (I have 6), run a system diagnostic for each device separately (really really long process), run other programs they sent me and upload everything for the Apple engineers. In-fact, the engineers actually asked me to take my camera and physically record myself plugging in the devices and to show the result. Long story short. I spent 10+ hours on the phone and screen-sharing helping Apple gather information to fix this problem in the future. Later, update to this beta and repeat, over and over. The result? "We don't know when it will be fixed, so please return the iMac and here is a coupon for $100 off your next purchase. The coupon doesn't work on most items, including iPads. I really feel discouraged that I was used as a science experiment and their solution is to have me return the iMac and for my lost time, a coupon that doesn't work on anything. Really its super discouraging, I really do like the iMac other than its issues. Who, in your experience, is the person / department I can talk to about my concerns? TL;DR. New iMac issues, 10+ hours of Apple using me to gather data for engineers to fix TB3 issues in future release. No solutions. Asked to return iMac and given a $100 coupon that doesn't work on anything. Who can I talk to for a better solution?