You sound like an expert, but I was very surprised to read this. I bought a Nespresso on Amazon and ended up returning it because the liquid it put out tasted, to me anyway, to be anything but espresso. I tried all the capsules in the sampler pack and disliked all of them quite strongly. I think the biggest turn-off was the fake crema which the machine whipped into existence somehow, but wasn't actually anything like real crema, and ruined the shot in my opinion. There was a front-page post yesterday about the science behind crema, possibly what prompted this post.
I encountered my favorite machine in a house I rented for a couple years which had a built-in/plumbed-in Miele CVA6401, and it consistently produced the best single-touch espresso I've had, with no maintenance except descaling. It didn't compare to a very good coffee shop, but for at home espresso, I'm saving up to get one in my kitchen.