IEOs and ICOs are just as risky, but If I had to choose between the two, I would prefer the top IEO in the market because there is less risk of fraud compared to ICOs. The IEOs listed on Binance are successful and have attracted more market investment as well.
Every investment is risky but IEO still provides a little investors protection while some are not (although that also depend on the exchange where the IEO is held) cause exchange Binance usually collect some certain amount of fund from project owner which will serve as investors protection incase the project team exit. However, this also doesn't guarantee the project prosperity because the project concept and community support is also needed.