The machine made excellent espresso.  Steaming/frothing milk was fine.  The 58mm portafilter is definitely the way to go.   Heating up was pretty quick, and the switch between steaming and brewing temperatures was fine -- a bit of a hassle but unavoidable at this price.  

In the end, it makes a fabulous espresso.

My power button broke within a few weeks and the machine became unusable.

All the buttons, housing and other exterior parts are ridiculously flimsy and cheap.  The problem looked like a result of cheap and inattentive design, not a manufacturing problem, and so I have no confidence that other units of the same model would be any better.  It is a bit of a scandal that Gaggia keeps selling this machine.  

It is very cumbersome to remove the water tank in the Baby.

Amazon.com took it back and I bought a Gaggia Classic instead.   I've been very happy since then.

The espresso quality was great, but the construction of the machine was extremely poor.  At $400, you should expect a machine that will last years, not weeks, and I can't see this unit doing that.  

Gaggia sell the same inner works with different housings and buttons at different prices.  After my terrible Gaggia Baby experience, I shelled out an extra $100 to get the Gaggia Classic.   The Classic  also makes consistently great espresso but has a much sturdier feel.  The buttons are much better, the water tank is much easier to get access to, and it feels like it will last a while.   I ended up annoyed at having to move up the price chain, but at least now I'm enjoying good espresso while being annoyed.  The steam knob on the Classic is also a huge improvement over the weird 'pimple on top' knob of the Baby.

Avoid the Baby; get the Classic.

Amazon was very helpful and prompt and accepted the return no questions asked (and they even paid the return shipping).