I recently ordered the Nespresso Lattisima Plus which is the newer version of the Nespresso Lattisima. There are several pros and cons to this machine over its predecessor. It has a much smaller footprint, both in height and width. That compactness comes at a cost; however, as the water tank is smaller and there is no heating element at the top for your cups. I also owned the old one and never bothered to wait for the cups to get warm, so no loss there. The milk frother on the Plus is also more compact, and easier to clean. The old version held more milk, but had more curves in it which were hard to clean without a special brush. The coffee heats up to a higher temperature and the machine reaches that temperature faster than the old model.
The biggest draw to this machine is that you can make delicious European style cappuccinos and latte macchiatos with minimal effort. You can't get that type of coffee out of a Keurig, even with a separate frother.
Now, of course the capsules are more expensive than traditional filter coffee; however at .65 cents per cup, the capsules are cheaper than Keurig capsules and stay fresher longer. The Keurig capsules are not sealed. There is a convenience factor with Keurig over Nespresso as well, since you can only get Nespresso capsules online or in hard to find specialty stores. However, if you order a few days out you'll receive the Nespresso capsules right at your doorstep. Finally, the price of a Nespresso is generally twice as much or more than the Keurig models. I bought mine "used like new" and saved nearly $200. In a jam, you can order the capsules from 3rd party sellers on Amazon, but expect to pay a .25 to .45 cents premium per capsule.
Bottom line: If you are a fan of European style cappuccino and latte macchiato, then this is the machine to get. If you're more of an American coffee fan, then the Keurig is a better choice.