TV Watermelon is great. The V4L cartos are a little sweeter than the TV. I wouldn't say either actually taste like real watermelon (which I think is a good thing), but TV's is closer than the V4L. I almost got a little sourness from the cartos, which was awesome, but only for a few minutes...and I've never had a sour watermelon.
It's a pretty mellow vape for a fruit flavor, which is why I like it so much. It has a lot of flavor, but it doesn't blow you away. Watermelon would get sickening if it was too sweet. This is a solid all day vape.