Quality Health is in most insurance / network plans.
As long as you are not a hypochondriac, their doctors do seem reasonable - do your own due diligence on the meds / follow ups that they might put you through.
Also, for us - walking into the Canossa Hospital's outpatient department in Mid Levels earlier in the day has had good results. Most hospitals have reasonable OPDs.. some even have family medical practices in and around Central - check to see if Raffles, Sanatorium medical practices are covered..
Unfortunately our go to GP is not the best for short wait times (2-3 hours during rush hour / no appointments).