I am also in Grand Promenade, although technically it is in Sai Wan Ho ... just a stone's throw from Quarry Bay and Taikoo Shing.
I can echo Chriztina's comments ... lots of very nice assets to the complex itself, excellent staff, lovely sea views, and quick access to any form of transportation - mtr, tram, and bus stops are all very close and taxis are plentiful right outside the main building. In case you are interested, there are many children here and a lot of facilities for them; also there are tons of pets (not annoyingly so ... I just mention it to let you know they are quite welcome here).
There's really nothing to complain about residing here. Sai Wan Ho is a relatively 'local' area, with the requisite wet market, shops and restaurants ... quite charming to walk around and explore. Yet, as stated before, there is a Park n' Shop with an abundant selection, a nearby mall and movie theater, and a trendy restaurant/art gallery scene. It is like having the best of both western and eastern worlds right at your door.
I don't think you could really compare it to mid-levels. I'd say there are far fewer western expats here - GP and Les Saisons seem to be populated more by eastern expats (Japanese, Korean, etc) and Sai Wan Ho itself is almost completely local. That said, there are still a good number of westerners around and regardless, it's a friendly enough place ... doesn't matter where you are from.
Hope that helps, good luck on your search.