Late yesterday I took up an invitation from the processor architecture firm ARM to go hands-on with the HTC Dream / T-Mobile G1 / first-bloody-Android-phone-out-the-gates.
I won't bore you with photos, since you've seen a demo already, but I will offer my opinion on the thing. First off, it's fast. Maybe a bit slower than the iPhone, but not by much. Having an iPhone-esque capacitor touchscreen helps - this is not your standard, relatively draggy HTC screen. The phone dialer works responsively - a small point perhaps, but rather important in a phone (hey Microsoft, you listening?).
The app store is somewhat underpopulated right now, but it looks to be a seamless affair. The preinstalled Google apps (calendar etc) look nicely done, but that would need more hands-on experience for a proper, comparative opinion.
The UI is intuitive, and everything seems to work quickly and well. The iPhone is clearly a template for some of the menu systems, and why not I say. The nice thing about it is that the menus have the consistency of iPhone menus, while having the granularity of Windows Mobile menus (those of you who've played with recent, multiple-UI WinMob handsets will know how inconsistent and confusing they can be).
There are three input methods: trackball, screen and keyboard. All are good. Although the keys on the keyboard are a little too flush to the surface for my liking, they are nicely sized and spaced out. A surfeit of input methods can be a sign of weakness (jack of all trades etc), but in this case - and given that the G1 is a first try at a whole new ballgame - I think it's justified.
The build quality is pretty darn good. It may be a plastic phone, but it feels fairly solid for it. My only caveat in this department would be applicable to any handset with a sliding keyboard - that the sliding keyboard can make it feel just that little bit less sturdy. Nonetheless, the thing slides well.
That said, the curvature of the handset towards its base does seem rather odd. Idiosyncratic as it may be, it will probably be a turn-off for some, who may find it makes the phone feel needlessly thicker. Ergonomically, in landscape mode, it may make sense though - I'd need more time with it to decide.
The G1 is not perfect (the camera sucks, for instance), but it is a genuinely exciting phone. It's the closest I've seen anyone come to replicating the ease of use and common sense of the iPhone and its UI, it's well built and it will prove an excellent first step and testing ground for Android. And, if it's priced decently in the UK, it would be a no-brainer to pick up as both a decent handset and a piece of history.