Not impressed.
In my case quite I am impressed since it would appear the developer has liaised with BT, put its hand in its pocket, and ensured that they can market the development as having ultrafast broadband, or whatever is the word of the day for a 330Mbps service.
As for the continual delays you are experiencing, you have my sympathies. I'm in a similar position on a 2-3Km EO line (39dB attenuation) here in central London with no BDUK funding and little or no BT funded network rearrangements likely in the near future.