It really depends on what rocks your boat. There are some area in Wanchai similar to Kennedy town, like Star street or stone nulla in terms of restaurant. Kennedy town is wide, more space to walk around and less people. Close to the sea side but then it's all concrete. With the MTR prices have increased a lot and most bar/restaurant are getting more expensive.
Wanchai, it really depends of where you live like other people said, The flat close to Kennedy road are a lot more quiet like Phoenix court etc.... Hennessy road on the other end is super busy and noisy.
North Point, I stayed in a hotel there for 1 month, it's quite crowded, I didn't really like the area, flats are cheaper but you're quite far away and MTR is crowded most of the time. There are also a lot of Chinese tour stay in the area at night blocking the street which can be annoying.
My advise is go around and see if you like the area, try going at different times in the day, like time you would expect to go home after work and during the day in the week. Wanchai in the evening is okish, during the day it's a lot busier and crowded. K town is pretty much ok most of the time