The Globe and Mail reports in its Saturday edition that some of the world's most sophisticated private real estate investors, including Canadian pension plans, say scores of properties they own are holding most of their value. The Globe's James Bradshaw and Tim Kiladze write that by contrast, investors are dumping shares of publicly traded real estate investment trusts (REITs), particularly those that own skyscrapers. In Canada, the national vacancy rate of office towers just hit an all-time high, and in New York, there are enough empty offices to fill 26 Empire State Buildings. Despite the headwinds, major property owners, including Brookfield Asset Management and Blackstone Inc., argue the process of valuing commercial real estate today is nuanced. Even in the office sector, they stress that quality matters. Newer towers with modern amenities, known as Class A buildings, are seeing higher occupancy rates and rising rents, while older, less well-maintained buildings, often located in suburban areas -- the Class B and C inventory -- are emptying out. There has been "an absolute bifurcation of the real estate market," Connor Teskey, president of Brookfield Asset Management, said on a conference call last week.