A chain drive driving through an internal gear drive will always be more friction than just a chain drive (assuming the chain drives are similar). However, as an Afline owner, I suspect this is probably only measurable in a lab. I love my Alfine (an 8s one).
I suspect the main sluggish contributor difference is in the weight of the bike and electrical assist, coupled with the resistance of the electical system powered by you when pedalling, rather than any fault with the hub.
Oh, and tyre pressures of course. And tyre weight. And rim wieght. etc. I’d love to know just how much the full bike weighs?
Rob
bigrobracing.co.uk