I think NEO and IOTA are both good holds, but I personally put more faith in NEO as it is much further ahead in development. 2018 is a big year for NEO, while IOTA is aiming more for 2019-2020 I think. It kind of sucks that you missed out on the crazy IOTA gains, but I personally feel like NEO, despite it's gains, has not had 'crazy gains' yet like some other coins have. I feel it's overdue for NEO to do something like Cardano, TRON, XRP or RaiBlocks did. But massive spikes have not been NEO's thing too often, so perhaps I'm mistaken.
I dare not let go of my NEO, though! I just know the moment I do, it's going to shoot up like crazy and I'll regret it forever ;)

I will have to look into Neblio, i don't know much about it yet