Dear Mad! 
Over the years I think the whole glanduliferum vs. praestans question has spurned, even preeminent, botanists to take very different positions in relation to proposing an answer/explanation. Not seldom, themselves over time changing their minds (if my memory doesn't elude me, Braem is an esteemed example of such a one). The whole kerfuffle wasn't diminished by the introduction of P. gardnerii into cultivation - and by P. wilhelminiae sometimes brought into the discussion in rather confusing ways (read: by misidentification).
As Rudolf (GuRu) pointed out above, the current stance of Kew, is at the moment to accept P. glanduliferum as species name with P. praestans relegated to synonymity.
You mention, in the passing, your scepticism in relation to the taxonomic status of P. ooii. I have had the great fortune to see a clone of this rare species in flower in the nursery of my friend, Hans Christiansen. And I assure you, that it is very different from any other Paph-species, I've encountered. That might not count as much, but Hans with his vast knowledge of orchids and more than 50+ years as professional nursery owner plus long term experience as international orchid judge, totally shares the same view.
As I'm not going to bother Sam with a request for pictures of his flowering plants of this cross, your input with pictures to compare, when your plant is in full flower, will be highly valued!
Happy New Year to you - and to y'all!
Most kind regards,
Jens
