Great machine overall. Espresso is better than many coffee houses. Steam quantity is good once it gets going. Fast warmup overall. Saves so much time in the morning. 2 year warranty on new models from delonghi.
Negative Product Points
If you forget to press the bypass doser button before adding pre-ground coffee, it makes a mess inside the machine. Steamer squirts out fair amount of water before steam starts, so don't start into your pitcher until you see steam. Steam knob feels flimsy.
Detailed Commentary
These are great machines and others have already provided great overviews. I wanted to add some tips I have found working with the machine. I have the esam4400 without the milk frothing pitcher, but all of them are the same internally.
I think everyone notices that the frother creates too much foam. There is a siphon hole on the frother attachment that pulls in air. If you put a piece of tape over the hole, it solves this problem completely. You can then control the foam and pull the milk yourself until it fills the pitcher, then submerge the frother to continue heating it without making more foam.
The bypass doser states to use 1 level scoop max, but it creates very weak coffee. I have found the machine has no problem using 2 level scoops, which will create a puck the same size & strength as when the machine grinds the beans. But no more than 2 level scoops!
Adjusting the grind size to get the right brew time may take a few pounds of practice beans, but once set it is consistent. I have found some behavior that isn't described in the manual: When you are using the "steam" wand, you will hear the machine pulsing as it pumps water into the boiler for steam. At the same time, the machine pulses the grinder and checks to see if it moves. This is how the machine is able to detect if the grinder is stuck, strangely while you are using the steamer wand. So If the machine becomes noisier when it is pulsing, you probably have too find of a grind; the machine will tell you "too fine" if it can't move the grinder at all, so you can adjust it. I just thought I would mention it, so you know why the machine can become noisier sometimes when steaming. It isn't broken.
The water temp is adjustable to 3 temperatures.. (cool, normal, hot) so you can adjust it for the brand of coffe you are using, if you need to. But the default is good if you get the grind size right.