I have bought this machine two years ago, looking for something more to get out of my coffee than what my stovetop "espresso" pot could provide. Being briefly (but only very briefly) tempted by a Nespresso, I first considered buying a Silvia, but was held back by her capricious reputation. Some of the reviews here had nice things to say about the Gaggia Baby Twin, especially its ease of use and its temperature stability, which, I thought, would make it relatively easy to produce consistently good shots. The idea of being able to steam easily with this machine was also tempting as I love a good cappuccino every now and then. For a grinder, I bought the Ascaso I-mini (especially for its size) which has its usability issues but does deliver a good (and very fine, if needed) grind quality. Good enough for the Gaggia in any case.
In the end, cappuccino is what I enjoyed most with the Baby Twin. Funnily enough the manual doesn't explain how it really works: turn the steam knob and purge the remaining water from the thermoblock. Wait until all the lights flash and close the knob. Open it at any given time and you have good steaming power. Taping up the hole on the side of the "pannarello" makes microfoam possible - it has all been described elsewhere on this site. Anyway, this is how I make my cappuccinos, which I still consider infinitely more tasty and textury than anything I can get in a café or restaurant - at least here in France. By the way, I haven't had any issues with bad smell or taste when steaming milk, as some people here wrote.
Straight espresso is somewhat of a different story. Temperature may be stable on this machine - I haven't checked it myself but I'm willing to take other people's word for it - but in my experience, and notwithstanding all the tamping, dosing and distribution techniques I have tried and mastered more or less successfully over time, shot quality is never more than "decent". Shots tend to blond early, bitterness is often accentuated and I cannot help having developed over the past two years a feeling that my Gaggia has its limits in terms of pure espresso quality.
Of course, I realise that I myself may be at fault here, that my technique is still lacking in many aspects and that I still can improve even on the Baby Twin. But as things go, I am looking now to upgrade to an E61 machine which I hope will help me to get me a few steps closer to the heavenly espresso stories I read around here. Also, having a decent steam wand instead of the "pannarello" type that Gaggia supplies, would be a good thing.
Lastly, the machine started leaking water some time ago; strangely enough, there appears to be an opening in the bottom of the machine at the point where water from the solenoid valve flows into the drip tray. Most of the water flows past this hole, but some manages to escape from time to time, which is messy and annoying. It seems weird that Gaggia would have designed it this way, so I might try and repair this fault.
In the end, I have been quite happy with this machine most of the time. It is easy to operate and it looks great - which can be a compelling argument for the non-coffeedrinkers in your household (in mine, I am the only one). It is also a very good machine to learn espresso making skills on. But at some point, upgraditis will inevitably kick in...