It looks and feels every bit like a 35mm EOS, and that's exactly what Canon wanted, to the same degree it's like no other EOS, lots of little design touches and styling make it obvious that the D30 was destined to be a digital from conception. Despite having a "plastic" outer skin the D30 is surprisingly strong with no sign of flex, everything feels solid, if you take a look at the cutaway image below you'll see why, there's a strong metal substructure.
Canon were keen to point out that everything from the lens mount back to the CMOS sensor is a solid metal box, you can also see that the entire back is supported by a solid sheet of metal, all in all the D30 is very well built for a "consumer digital SLR". In your hand the D30 feels very good, weight balance is good and compared to other digital SLR's it's a lightweight (even with the optional battery grip). Seem lines are tight and there's not a creek or body flex in sight. All in all I'd say that build quality is excellent. Any improvements? The grip could have been deeper with a more pronounced lip on the front (1v style).
In the cut away diagram of the D30 below we've identified several components (internal and external) which may be of interest.
The D30 features several interesting internal components, the mirror having a semitransparent area in the center which provides an image to the AF sensor below, above, attached to the viewfinder prism is the cameras E-TTL flash sensor which works by measuring the exposure of a pre-flash just milliseconds before the main flash (only works with the onboard flash or Canon EX Speedlights).
Sub-note: there was a suggestion / question to the manufacturers from our discussion forum: Wouldn't it be possible to make the whole of the mirror semitransparent and replace the AF sensor with a cheap CMOS / CCD unit (say 850 K pixels) which could provide AF information and the ability to have a live preview on the rear LCD?
The CMOS sensor mounted exactly where you'd expect it, protected by the anti-alias filter which is situated immediately in front of it (and not removable). On the outside of the camera you'll note the AF assist lamp which doubles as a redeye reduction lamp when taking flash shots.
Here's a size comparison of the D30 beside the only "other brand" competition (at the time of writing this review), Nikon's D1. The D30 (body only) weighs in at 0.89 kg (2 lb) with one battery, with the battery grip (shown) and two batteries it weighs 1.27 kg (2.8 lb), compare this to the D1 (body only) with battery at 1.42 kg (3.1 lb).
Notice how the shape of my hand changed with the optional battery grip, this definitely makes the camera easier to hold in one hand (although you would almost always be supporting the lens with your left hand).
Rear LCD Display
Top Information LCD
It's probably worth noting that this isn't ALL the information the LCD displays, when changing settings the LCD changes mode, for example the exposure meter doubles up to display bracketing information, the shutter speed can display ISO when it's being changed etc.