[jsingleton]

It depends where your starting point is. Core bundles a lot of stuff together that was previously separate or just good practice. If you are familiar with MVC / WebAPI / EF / OWIN and already doing DI / Logging etc. then it's not much of a leap.

[avgDev]

This is correct. I did not use DI before moving to Core and that was probably the toughest. Once learned, DI is great.

MVC 5 to Core should be a pretty easy transition if you know DI.

[nikon]

I feel "DI" in the context of .NET Core is often the IoC container you feel forced to use. DI is a pattern, but even trying to use the logger extension without the service provider is a pain.