I hope Miguel is right: the tree is so pretty and the perfume of the flowers is excelent, but it's better if it brings good tasting fruits.
Guabiju is very variable, for now I tried only some fruits the last year from a tree at Buenos Aires and I liked it a lot, the skin was sour and the pulp very sweet (not as sweet as the black surinam cherry), so it's better to eat only the pulp; the seed maybe it's too big for this little fruit. The flavour was not comparable to anything I know. I want to do some jellies based on it, they say it's great.
My fruits are about to be ready now, see:
I almost cant resist the temptation, but will have to wait 1 week or so...
Happy new year!