I don’t live in Southern California, so just because a pear does well in the SE does not mean that it will be the best in the SW. That said, the first question is what do you mean by “low chill.” Magness, Warren, Ayers, Patomac and numerous others require about 800 chilling hours. All of them will do fine many warm climates, and in most of Georgia, but are probably not reliable here in Statesboro and certainly not closer to the coast or further south.
Tennessee requires about 600 hours and will probably be OK here. We barely got 600 hours this winter and it bloomed and produced a crop just fine. I have heard chilling hour estimates of around 400 hours for Tennosoui and Southern King. Goldenboy came from Wacilla Florida and probably needs between 200 and 300 hours. Southern Bartlett (tasteless for me), LeConte, Baldwin, Florida home, Courthouse, Scarlett, Orient, Cajun Pineapple, Carnes Karric, Acres Home, and Southern Queen are all low enough chill to grow in parts of Florida. Now, if you are in Zone 10 the low chill pears may not be low chill enough. so it all depends on what you meant by low chill.
Marcus