I concur with Simon regarding the problems with turpentine rootstock in our area. I have tried growing both trees on grafted Manila/Ataulfo and Turpentine with the same variety. JF (Frank) experience and opinion is a minority point of view on this forum but if it works for him that's great. Over the years I have found three key factors in Succesful mango growing in SoCal.
1. Choosing a vigorous growing variety. Cac, Coco cream, Sweet Tart, Buttercream, Seacrest, Orange Sherbet, Lemon Zest, Fruit Punch ext. Avoid slow-growing mangos like Ice Cream, Kesar, Julie, Dot, Pina Colada exct (do your homework).
2. Choosing the best rootstock for our area. For me, the Mexican varieties work best. I particularly like Ataulfo grown from seed but Manila also works well. Kent is also OK but I still prefer Ataulfo as it is the fastest-growing for me.
3. Planting in the right soil to maximize mango growth. Sandy Loam soil with 15% pumice works the best based on my experience. Clay soil works the least well. If you have clay soil the mango tree will still grow but at a much-reduced rate. It's harder for the small fibers of the mango tree roots to penetrate clay soil vs more of sandy soil. Drainage is also much better with sandy loam soil. The mix I like and have been using for over the years is 65% sandy loam, 20% course washed sand, and about 15% pumice. I buy these items in bulk.
All three items listed above are equally important but the third item is often overlooked.
Also as a tip do not let young trees set fruit as it takes energy away from foliage production.
Here is a photo I just took today of my sweet-tart on Manila that was grafted 3 1/2 years ago. It has small fruit forming now. This is the first year I will let the fruit hang and mature. My focus for the first three years was on growth.
Johnny
Sweet Tart on Manila (3.5-year-old)