As you say, there's a bewildering choice of hotels, but here's one more suggestion; the Cordis in Mong Kok. Stayed there pre-covid and really liked it. Mong Kok itself is a very vibrant/busy area, not touristy, which may or may not appeal. Just a few steps to a metro stop, though, so always easy and quick to get to any tourist spots.
For your budget you can get the rather spacious and comfortable Studio rooms which have great views.