A recommendation for a good 3* hotel is the
JJ Hotel in Wan Chai.
The rooms are quite large, immaculately clean, ok sized bathrooms (not small) with a good shower, plenty of clean towels, great storage space and a safe in the room. Air con works well and large king beds (separated for two twins).
There are no amenities such as pool, and the hotel is located on floors 9-12 of a larger building.
I have stayed in many properties around the same price range (HKD700 a night) and this is by far the best... I now only stay elsewhere if I don't book far enough in advance and it's full (which is almost always).
It is easy to get to with airport express followed by taxi. And ding ding (the tram) is a one minute walk away to get into Central.
Only downside is that the bathroom has glass walls. There is a blind which can be lowered, but there are still cracks at the side... so if you were travelling with someone you were not quite on those terms with it might not be so comfortable