FWIW - about a year into playing, due to family circumstances there came a time when I could really only get on my kit for a few hours one day a week. Other than that, I only had late at night to practice, when the acoustic kit was out of the question. I bought an e-kit. It was great for practising independence exercises, sticking, working out sheet music. And then one day a week I could transfer to the acoustic kit. Having spent the weekdays working on the mechanics, I could spend those few precious hours on the acoustic kit concentrating more on the sound, feel, dynamics.
I agree with what everyone says about using e-kits to learn on, if all you have is an e-kit. But having both, I actually found practising on the e-kit was beneficial in a way because it helped me understand - in those early days - what dynamics etc. actually meant and eg the range of sounds I could get from real cymbals (and indeed the joy of playing real drums after a week of not being able to).
When my family circumstances changed again I hardly used the e-kit. But it's still handy if I just want to work something out (quietly).
