I have a sweetheart (in ground 11 years) that has fruited for the last two years, and has been a somewhat shy bearer but the fruit are delicious. I was tempted to pull it but Rob (bsbullie) encouraged me to be patient and gave me a few tips which I am glad I took, and I kept it.
My Mauritius (in ground 10 years) which was far smaller when I got it has it's first crop this year and this first crop seems a couple of weeks behind the sweetheart so I've tasted but a few but they were not as good as the sweetheart which is more juicy and sweeter.
Both are handsome trees with a nice not too dense canopy, they are my fave trees.
Reading that longan may require less chilling hours, I wanted to hedge my bets on fruit availability so I planted a Biew Kiew longan (in ground 5 years) from the seed of a fruit I had 8 years or so ago.