I first discovered this fruit on the streets of Cyrildene (China town in Johannesburg). Their massive size intrigued me, so I bought one even though the man tasked to sell it wouldn't tell me what they were. After describing it to my parents over the phone I have a name! We call it "you zi".
More recently I have seen pomelos (thanks for the name shop signage!) popping up in all my local grocery shops - I like them, though I can only eat about a quarter at one time. It's wonderfully aromatic, a good balance between refreshingly tart and sweet citrus flavours! You can use them in salads and savory dishes too (kind of like your pomegranates, mangoes and peaches - hooray fruit!).