Jim, another splendid analysis!
Somehow, I got the impression that PTC emphasizes the 3D functionality too much. All their arguments circle around the grand 3D plot capabilities of Prime. This reminds me of another 3D issue. My company uses Creo (another PTC product) and is in constant struggle with PTC to get a decent 2D tool for technical drawings. PTC's usual answer is that nowadays nobody needs 2D anymore. They are, as a german proverb goes, immune to advice.
Raiko