The only shape of loquat in my memory was round (and small), but I never questioned why it's called 枇杷 (pipa; the same pronunciation as a Chinese music instrument).
This time, I saw big elongated loquat (枇杷) at Hangzhou Airport, and was wondering if it's GM food. Well, I bought three big ones in Xiamen myself, because I wasn't sure how sweet they were. One of them was so sour that I had to give it up. When I told that to my colleague at Xia Da, he packed me a heavy box and told me these should be sweeter than what I bought. He was right! (Note: They look more like the ones in the first photo, at least in terms of color and size.)
If you are in Hangzhou and want some, leave me a note so that I can contact you. I don't think I can eat them all by myself.