IEO is also a token sale but the different is IEO hosted by exchanges, so it's like a partnership. In my opinion IEO is better than ICO, because investors can invest their money easily on IEO using the exchange like binance.
IEO is more popular than ICO right now.
yes I prefer investment using IEO which makes me reliable, but it depends on each in choosing the project. according to me it is very good. because in using the IEO to avoid project scam and fraud