I've had more time to inspect my example, and can see the same issue with the windscreen, but to a lesser extent. The side windows don't have this problem, so I wonder if its similar to the prismatic effect on the new Mk1 coaches available from another N gauge manufacturer. I've not removed the glazing, but it appears that the glazing plastic does not meet the bodyshell at 90 degrees? My Physics master would have me in detention for forgetting this, but refraction springs to mind?
Anyway a Digitrax DZ125IN fits no problem. Running was very smooth if a tad noisy, but it only has a length of flexi track to run along at the moment, and the oil may not have yet reached all the gear teeth.
Paintwork is top notch, nice sharp lines to the yellow edges and a nice colour consistency. When running on DC the lights were bright before the loco moved, and on DCC they were very bright. No damage to the motive units / coaches, but other than being sent to the retailer is has not been through the postal sorting system.
Overall a very happy Dapol HST owner. Looking forward to the 26, 52 and whatever else will go with the LNER tender