Most espresso, the crema tastes good, the remaining liquid is quite offensive. You get creamy mouthfeel but at the bottom of the cup, it's like bile. I guess the triple ristretto all crema pull makes sense for that. Get only the good stuff and avoid the bad. The reverse being where the crema is blah but the liquid underneath is excellent. People who fancy the coffee like wine analgoy lean this way. To me, the best espresso I have had are smooth and consistent from top to bottom. The crema is tasty and the resulting liquid underneath is excellent also. Not only that, but it also is enjoyable as it begins to cool. How many espresso really qualify as this?
Part of why I am such a fan of Andrew Barnett over at Ecco Caffe (besides his zen master knowledge and humble nature) is his roasting style lends to soft flavors in espresso, top to bottom. The coffees typically have flavor consistency from crema to last drip. Even as the coffees begin to cool, it's tasty. It's been part of my learning curve of graduating from kick in the face intense flavors for my beginners palate to the more subtle flavor profiles. I now have a strong desire for sweetness and complexity over sharp peaks and intensity.
I guess I yearn for espresso to be something so tasty that the average coffee drinker could have an espresso and go 'wow, that's tasty', not 'whoa that's intense'.