Retail seems toxic these days, NL retail REIT's (like Wereldhave) are underperforming as well, online shopping has made it to NL without the help of Amazon :) However, the amount of US retail supply (pp) is not comparable to the NL, and the US (10y) treasury yield is well above NL yields (2,81% vs 0,65%). So lower NL retail yields can be justified by (on average) higher quality and a lower yield environment.
The best NL prime offices are at the Amsterdam Zuidas, where yields have fallen below 4,0%. NSI has some quality office assets around the Zuidas. The offices NSI has been buying the lately are not the best (AAA) locations, as these yields are probably too low. But the assets are concentrated in well connected office areas (Amsterdam, Randstad region). Sloterdijk (Q-Port, Glass House) was a very weak area a few years ago (around 2013), a lot of empty offices when recession hit. Ihe area is very well connected and has come alive recently, as some offices were converted into other uses (residential, hotel, etc), and economic conditions have improved significantly.
NSI is not aiming for AAA office quality, after completion of the asset rotation the office quality can probably be labeled as A. For now the overall quality is lower, as NSI still owns some lower quality regional offices (high vacancy rates).