A note on my experience regarding “illegibility” of the current Heritage 300. I own it and owned the previous version (virtually identical to the Spectre except for the bezel and small changes on the dial). I don’t find the new version illegible at all, either indoors or outside. It does have slightly more reflections due to the fact there is AR coating only on the underside of the crystal, but the reflections are nowhere near as bad as on the old uncoated Rolex box crystals. In certain conditions, those would just be a silvery sheen and you couldn’t see ANYTHING until you twisted your wrist.
The only “illegible” part of the Heritage 300 dial indoors (at least for me) is the sandwich 3-6-9-12 numerals and the Omega logo and model name. They are sometimes hard to see in dim light, but the main indices are very clear. So it is not at all difficult to tell the time at a glance. Since the “illegible” components are arguably decorative, it doesn’t bother me at all. But I can understand that some might want to see them.
On the older version, where the 3-6-9-12 and Omega name/symbol were painted on with a silvery-white, highly reflective coating, these were more visible in dim light.