As you know IEO trend is growing but i feel IEO is profitable only for those who invested in token sale but who have purchased altcoin after launched they suffer loss majority of the investors ,as the BTT and some other altcoin examples of IEO.
I mostly like IEO because for ICO we have to wait for long time that after finishing ICO token will come to market then profit or loss. But in IEO we can see present condition of market and if we include here roadmap plan of that company we can easily buy token in IEO or not.
So i think IEO is best.
indeed for the time being IEO is better than ICO. but many rich people from investing in ICO in 2017. and I see no IEO that is as exciting as the ICO before. but everything has a time, and for the time being I think IEO is safer