I think Raiblocks is a really promising coin and it is hard to understand why it is that much under the radar for most investors. Everyone is looking to IOTA because it does not have any fees but there exists Raiblocks with the same feature much longer and has only a bit of the attention IOTA gets. Hope this will change soon. I bought a good stake of Raiblock coins.
IOTA has gathered attention because of it's supposed ability to solve the scalability issue which all cryptos seem to struggle with. Though its ability to actually do what it says is heavily in doubt. The whole zero fee feature is more of a secondary interest.