I had a similar issue with a client SP3. Core i7/ 256/ 8gb.
Samsung LS24D590PL/ZA
Cable Matters Mini Display Port to HDMI (1019-10)
Fosmon HD1912 15-Feet Mini Display Port to HDMI
StarTech Mini Display Port to HDMI (MDP2DPMM6)
The Cable Matters cable would NOT fit into the docking station. The dock has a slightly angled connection and a very narrow fit. The Cable Matters cable is tapered on the MDP end.
-Connected Surface directly to monitor with cable. The Surface had a lot of trouble detecting the screen.
The second cable did indeed fit into the dock BUT would NOT show picture on the monitor.
-Connected directly from the Surface. The screen would come on (sometimes) BUT the picture was poor. The client even complained about it. The resolution did NOT look correct.
I am on my third cable. I have NOT been back to the client site since.
I can't yet tell if this was an issue with the Samsung monitor or the Surface itself. In either case, it is frustrating to eat time on something that has been standard for more than a decade. Take a computer (or a dock) and connect to a monitor and get a picture.
No Updates available. I have NOT yet gone to Intel. I would do that for any other vendor's equipment BUT at a certain point, Microsoft should be able to get updates for their entire system as manufactured and put to market by them and only them.
I was able to use a different Surface Pro 3 (i5/ 8gb/ 256) with the Cable Matters and a Dell UltraSharp 2208FP. It did work the first time BUT I couldn't keep it on long enough to evaluate picture quality or resolution.
If Microsoft wants to get this whole hardware-software advantage piece off the ground- more should be done to guarantee compatibility. Test and give (5) cable recommendations. Test and give (5) monitor recommendations. Then we all have a baseline to start our troubleshooting from. Chasing tails (and tales) is crazy and costly. This feels like a repeat of Microsoft Mice NOT working with Windows ME computers.