We went to this mall because we wanted to visit the Masaai Market there and only had one day to do it. It's way out from the main part of Nairobi, though I think if you're with the UN, their headquarters is nearby.
The layout was creative and very interesting. There didn't seem to be a great variety or quantity of shops and most were very upscale and very expensive. They did have most the standard shop-types, but I didn't see a good bookstore. The masaai market was a lot of fun, but did seem quite overpriced (even when you spend a LONG time trying to bargain for a good price). The food court had a lot of interesting options, mostly in the same fairly pricey range with average quality. The food court area seemed like it would've been a lot of fun and relaxing, but it was under construction and thus really not very enjoyable.