IEO trend lasts for months and many projects I know changed their ICO plan to IEO. And obviously, IEO performed quite well. Like Huobi, Binance. While I am not so optimistic that it will live longer then ICO, Gate.io IEO is a disaster. And people start to lose faith in that. There will be nothing that will be living permanently. Same like ICO, the most important is do your own research, find out good projects and invest, that is the most important. Here is my list of projects that have the best future as of today (Including Alts):
Bitcoin
Ethereum
Stellar
Historia.network
BLOC
DGB
I am not so sure research can work with IEO platforms, looking at the speed at which IEO projects gets sold out, many people would have been on the queue and just focus on getting their slot filled, and if you take time to research while the project has been launched, the time used in researching is when someone is already filling up the available slots.
If these platform can only be notifying people ahead of the project launch, then it will give people time to research on such project before they further queuing up for participation, but I doubt if some exchanges will give chance since they want people to rely on their decision.