Harry, as you probably well know, cultivar quality is going to depend on place/climate grown in. So just because Alphonso is not great tasting in Florida doesn't necessarily mean it's not an excellent cultivar for elsewhere. That's why most countries end up developing their own cultivars which are best suited for the own conditions. This applies across the board to all: lychees, avos, citrus,etc. That's why it's very important for each location to do it's own research rather than rely on cultivars developed elsewhere.
Oscar