To address the Pickering question: I will reiterate the same comment I made as to the avocados. You can take any member's word for it but if you are limited on space, and have not tried it yet, I would recommend doing so before you buy and plant. You will find many with highly positive remarks on Pickering and by the same token, you will find some with average comments. I am the latter, while the tree has some very good characteristics, I do not find the fruit to be of exception quality. On the other hand, I did buy one for my parents as they have very limited space and do not have to worry about trimming, disease and will have the convenience of getting fruit of a smaller sized tree. While I have limited space, I would prefer to pick varieties of exceptional quality and utilize pruning methods to keep the size manageable.
As to the Edward: There are very few true dwarf mangoes (and the term is relavant, are they true dwarf or dwarf when compared to a 40 foot tree). Of the trees that will naturally grow slower and more compact, hence giving it or seeming like it has dwarf characteristics, I would say there is no dwarf mango similar to an Edward. There are, however, many that are of similar and/or higher quality that can be maintained to a manageable size by pruning. Again, bottom line, if you are limited on spce, I highly recommend you try the fruit before you buy and plant it.