I can't believe it's taken me almost 30 years to try a Rambutan. Actually, I'm sure I've tried it sometime in a prior life, but I brushed it aside as a "meh" and then quickly forgot about it.
Rambutan has the texture of a Longan or a Mamoncillo (spanish lime), meaning that the flesh of the fruit is a lot more firm and chewy than a Lichee. It also means that it's a lot more work to eat one. It has a slightly more citrusy flavour and none of the tonguebiting aftertaste of the Longan... bonus.
The spiky spines are somewhat intimidating at first, but they're actually kind of soft and pose no harm when you grasp the fruit and crack it open to reveal the shiny eyeball-looking fruit inside. Eat the flesh, not the seed. I was told the seed was bitter, so I took a bite (spat it out). Found out later that it's poisonous. Whoops.
Still not a rave. More of a "meh." Nothing that I would crave and make a special trip to buy. But then again, I don't really like Longans either. It's a texture thing.