Very odd - when doing a transmission oil change on my ZR (which is also a PG! gearbox), I found that the recommended 2 litres was ample (for some reason the recomended amount is 0.2 litre less for the ZR than for the TF; probably because of differing gears/differential, or possibly gearbox orientation) - oil was running back out of the level hole, so it was certainly up to the level plug. It is possibly worth pointing out that if the car is not reasonably level (ie. jacked up at one end for access underneath) this will significantly effect where the recommended quantity of oil come to in relation to the level plug
The oil that Rover recommended has changed a couple of times, and it is true that 10W40 engine oil was the recommended oil at one time. This was changed after they concluded that some gearbox problems that were surfacing were possibly related to the oil type, so they changed the recommendation to a more usual gearbox grade oil. The final change to MTF94 was done simply to enable them to extend the change interval to over 100000 miles from the previous requirement to change the gearbox oil at about 30000 miles. The MTF94 is simply a long life version of the previously recommended 75W80.
The fact remains that when a PG1 experiences problems, it is virtually always because there has been an oil leak and it has been run with little or no oil in it. There are rarely problems where the oil level is kept to the recommended amount.
Having been around Rover forums for nearly 14 years, this is the first time I have seen anyone suggest that the quantity of oil recommended by Rover is insufficient for the PG1
I don't understand the rather odd comment regarding a conspiracy by Honda - the same design of PG1 gearbox was used in a great many Hondas, with similar recommended oil levels and they didn't suffer as a result. Wherever the story of needing to overfill the PG1 has come from, I think it comes down to what could be classified as 'pub talk' or perhaps one of the more recent 'internet myths', or maybe a 'facebook fail' (some of the absolute twaddle that gets accepted as fact on facebook has to be seen to be believed!).