I have owned the Krups Gusto for several years. I've used it to make cappuchini almost every night.
This is a good machine for the money. Which is to say, if espresso drinks are not a high priority in your life, you'll be quite happy with the Gusto.
I have found the Gusto to be adequate, especially for the price. I able to make decent pulls from the beginning, and over time refined my technique to to point where I can get consistent results almost every time.
The Gusto does not make enough steam to froth 4 ounces of milk at once. It takes two "loads" of steam. Because of this, I learned that I had to steam the mike before pulling the shots, or else the coffee would cool off too much. This technique has a side benefit. The temperature of the Gusto is low. Steaming the milk first usually results in steam left over on the second "load" so I am pulling the shot with water still heated on the "steam" setting. If I didn't do this, the coffee would be too cool. I find that the Krups steamer wand with a second tube bringing in (or releasing?) fresh air works quite well. The thing does leak, I have to put a towel under the nozzle while it warms up and be sure not to leave the milk there or it gets too much water in it.
On the other hand, the knob to switch from hot water to the steam setting is difficult to master and poorly designed. A separate switch would make more sense. Another minor control annoyance is that the power switch and the pump switch are rocker switches that are mounted in opposite directions. The power switch is on when pushed to the right and the pump is on when it's switch is pushed to the right.
This machine's pump is weak. When I use a fine grind, the coffee comes out at the rate of a little more than one drop per second, which is way too slow. I mitigate this a bit by putting a layer of a coarser grind on the bottom of the basket to try and get some circulation. The crema is good with the fine grind, and this work-around is acceptable to me. A coarser grind makes a lesser quality espresso, but the machine handles it okay.
The machine has been durable and reliable. When we have company, I'll make four cappucini. It takes a while, but the results are appreciated.
I am upgrading to a Gaggia Espresso Deluxe, chosen because of the rated pump pressure and heating wattage. I selected the Gaggia based on my experience with the Gusto, if I did not have this experience (and the excellent product reviews on CoffeeGeek.com!), I'd feel much more ignorant in making my selection.
Other miscellaneous notes:
As a self taught barrista, I observe that the lower the fat content of the milk, the better the froth; I use 1% as it has enough flavor for other milk uses (cereal, etc), plus is less expensive than skim. I have also observed that the froth is not nearly as good when the weather is humid. My winter cappucini are much better than my summer ones.