I have yet to try Calcutta, Groff, Salathiel, Hanging Green (well, not sure about this one as I did try a green skinned variety in NY's chinatown.....it was not a very good lychee and so, based on the reputation of this storied cultivar I am assuming that either it wasn't Hanging Greeen or was not truly representative of it), No Mai Tze, Yai So or B-3. Have tried to grow No Mai Tze, but never got a tree to any size before untimely death. My current fruiting trees include Brewster, Mauritius, Kaimana, Kwai Mai Pink (Bosworth 3), Bengal, Hak Ip, Early Large Red, Garnet, Peerless, Ohia, and Farwell Ranch (probably Mauritius seedling) Also growing but have never fruited Seymour, Red Ohia, and I am still going to throw Sweeheart into this category. My trees have technically fruited but poorly and not in a way that has been represetative of their reputation (possibly read "hype). This cultivar is on double secret probation at my house. I have had a large fruiting Emperor.....but it died loaded with fruit one year.......I assume at the hands of some root destroying pathogen based upon how the fruit and leaves never dropped as the tree died.
My additional taste/flavor comments are: Kwai Mai Pink......excellent flavor but my trees lack vigor. Ohia........excellent last year, better than I ever remembered previously. Bengal......large fruit....equally large seed......good flavor, very prolific year in and year out. Mauritius......was really excellent last year.......can fall from excellent to the very good category in some years, but if you like a bit of tart along with your sweet, this is one to consider. Peerless....a probable Brewster seedling.....similar to Brewster....but more consistant crops. Early Large Red...not sure of the heritage. Tends to be similar to Mauritius....also a consistant bearer. Hak Ip.......great lychee for those that like the strong, somewhat medicinal taste of lychee. I do get that after taste referred to by Squam. The size of the fruit, smallness of the seed and consistant production makes me over look this after taste. Kaimana is large fruited, generally small seeded with a very unique floral flavor. Was a bit off this last year in taste and more so in production but usually is a consistant bearer at my house. With regard to Emperor.....when my tree was fruiting, it was doing so heavily and consistantly. The taste of the fruit does tend to be somewhat more bland than other cultivars. But, the sheer size of the fruit and its late season (consistantly the last lychees of the season at my house) makes this a must have.
Harry