It's not bad, the wind gets in there cleanly but to be honest unless you live closer to Lake Ill. than B.Bay I'd sail the Bay. The problems associated with Lake illawarra are; launch areas (fairly ****), weed (annoying) and general water quality (although this is far far better these days). Not that i've ever been sick sailing in there just some of it looks pretty sketchy.

Alternatively come and sail in the waves at Towradgi or Peggy's (south side of Sandon point). Peggy's is a pretty sweet spot if you're new to waves etc. It's a point/reef break so the launch area is protected and it's super flat on the inside IE you don't have to sail on the waves if you don't want to (it's basically a mini bay). It needs to be S-SE though, if there is any West in it launching becomes difficult as the headland blocks the wind somewhat.