The site should be well drained and sunny. These plants do best with little fertilization and very little extra watering. The typical misuse of irrigation systems (frequent cycles of short duration) can be a real disease inducer. The same goes for locations that are frequently rainy and cloudy.

I've seen Rapheolepis used extensively as a foundation plant, and a major component of commercial and private landscaping. It can be completely disease free if grown under suitable conditions.

We've had them in our church landscape for 6 years. No problems so far. They get fertilized once a year and are under irrigation.

I grow alot of them in my home landscape, and in my church yard as well. In addition to all that has been said, I would make this note. They do not do well in shade. They will grow lanky and not fill out well. They need at least half a day of direct sunlight. Otherwise, they are pretty near the perfect evergreen shrub IMO. One shearing once a year will hold them at the same size indefinitely.
OTOH there are no perfect plants, and Indian Hawthornes are not perfect either. When you do that annual shearing you usually have to scalp them to keep them at a certain size. They recover in about a month, though. To keep this problem at a minimum be sure to give them proper spacing so you don't have to be constantly reducing their size. I usually space them five feet apart. They will fill in that space within three years if planted in good soil.
Also, the pink flowering varieties seem to be far more susceptible to that spotting thing than the white ones.

mine in south louisiana are very tough shrubs. a set it and forget it plant. i have never fertilized them and never water them. they are great foundation shrubs. in fact, they are my favorite foundation shrub