Starbucks Barista is indeed a very good home machine with for its price, with a few flaws. I also included a video and some pictures below.
+First thing first is the plastic pressurized portafilter, which needs to be replaced or de-pressurized if you're up to pulling "real" espresso.
+Since it has a small broiler, this machine will pump fresh cold water from the tank to the broiler during the brewing process, the result is temperature drop through out extraction, which will impact the shot quality, for instance: sour taste, very blond in color, or thin crema.
+When steaming, if you wait for the ready light to go on and then start steaming, you will most likely lose steam power half way through while steaming your milk.
To cheat the machine:
Before I even talk about pulling shots, what you really need is a decent grinder that can does the job good enough, and fresh coffee beans. Two of the most important factors in getting good tasting shots.
+Replace or depressurized the portafilter.
+Make sure portafilter, grouphead, and cup are all pre-warmed.
+When brewing: Make sure to only start brewing when the broiler just finish its heating cycle. What I like to do is run some water through the group head till ready light goes off, then wait for the light to turn back on again. At this point you should already have the coffee packed in the portafilter ready to go. Right when the ready light goes on, turn it into steam mode, the broiler will continue to heat. Count from 1 to 11 thousand, then turn off the steam button to get back to brewing mode. At this point the broiler temp is is higher then the pre-set temp, more ideal for brewing. Insert portafilter and start brewing right away. By doing this, the brewing temperature will be more stabilized during extraction as the machine pumps fresh cold water into the broiler.
+When steaming: Start by pressing the steam button, the broiler will start to heat up water inside the broiler to make steam. Do not wait for the ready light to goes on. As the broiler is about 10 - 15 secs into the heating cycle, simply turn on steam knob for about 2 - 3 secs to purge out water, then turn it off. Do this about 3 - 4 times until the steam is dry. Start steaming your milk before the ready light goes on. By doing this, the broiler will continuously pump and heat water inside the broiler while you're steaming, this way you won't lose steam power halfway into steaming, which ensures a good whirl-pool motion inside your pitcher from start to end if done right. You will steam your milk faster by doing this too. And the result is a nice and silk milk which is ideal for latte art. I can say that the milk quality this machine produces is very very closed to milk I steam from the commercial machine is use at work, if not same since it has the original steam-wand.
Example of a good shot done right on this machine: www.youtube.com/watch?v=Brpmvre9E4o
Some pictures: www.flickr.com/photos/foocster/