First, all of these machines are capable of making good coffee – far better than any coffee brewed in standard American coffee drip machines. You will definitely taste the difference between espressos that you make with this machine over standard brews. Much better. However, don't expect much from the frother (panarello). None of these machines will produce the rich, dense latte froth that you will get in the best coffee bars (I don't count Starbucks or Cutter Point to be "the best.").
Saeco Aroma machines (the least expensive of the three I’ve tried) require you to grind your own beans or to buy an espresso grind. This is the minimum machine that you want for good home-quality espressos -- which again, will not be as good as the best coffee bars -- but will be damn good. This requires you to tamp the coffee grinds yourself, to dump the grinds, and rinse the filter holder, but in all other respects, it's as easy as the more expensive Saeco Vienna and Giro machines.
The Saeco Vienna and Giro are called superautomatica machines, because they do just about all the work for you (supposedly). The superautomatic machines will grind the beans, tamp them, and then give you a shot of espresso and dump the grinds into a bin. However, they require almost as much upkeep as the simpler Aroma machines -- the water holder is smaller, the machines are more finicky and require constant cleaning etc. The quality of the coffee is the same. What is important is a well-made machine and 15 bars of pressure.
I like the Saeco Vienna machine very much. Both it and the Giro require you to keep an eye on the water supply (the holder for the water is a bit small in both machines, so you do have to replenish the water supply fairly frequently), and to regularly clean out the used grounds, and dump excess water. The Vienna machine works well, produces great coffee, and is not so finicky that I have to constantly fiddle with it. It works so well, without complaint, that I often forget to refill the water supply or dump the grounds.
Unfortunately, the Saeco Giro is one of those “new, improved” models that is much worse than the original. I hear that Saeco got purchased by Philips, the Dutch corporation. I’ve rarely bought anything made by the Philips brand that worked well, and the Saeco Giro is no exception. This thing is irritating in the extreme. The water basket is small, so you have to refill it every two days. The machine has about six different sensors that will tell the machine that something is wrong; when something is wrong, a red exclamation point will come on, and it is then up to you to peruse the manual to figure out what is wrong. This goddamn red light turns on just about every single time I make an espresso (I drink about three per day). The causes of the alarm are as follows: low water level in the water holder, a random amount of water in the water “dump” area; the drip tray or ground tray or bean holder slightly out of place; low level of beans, etc.
I really wish I had bought a Vienna rather than this machine from hell. I don’t even think that it makes as good coffee as the Vienna. Oh, I almost forgot the most frustrating part of this machine – in their wisdom, the designers decided that every time you turn this machine on, it will spurt out hot water before spurting out the espresso. Therefore you have to put a cup under the spout to collect this used, hot water; then you have to put your espresso cup under the spout to actually get the espresso. Don’t buy this machine. Get the Vienna or something else.