The SX20 IS' body is almost identical to its predecessor, the SX10 IS. At 23 ounces, it's one of the larger, heavier cameras in its class. However, despite the plastic body it feels pretty sturdy and well made. It also retains the nicely separated stereo mics.
In addition to providing a custom setting slot on the mode dial, a feature of which I've always been a big fan, the SX20 IS' mode dial rotates freely for 360 degrees rather than stopping at C and making you reverse direction to get to movie capture. This is nice, and something an increasing number of camera manufacturers are doing.
The use of AA batteries facilitates the SX20 IS' large, comfortable grip (and big size). One of the new features added over the SX10 is a mini HDMI connector for playing HD video--also new to the camera--on an HDTV.
Canon uses the same simple dial and five-way navigation switch as the SX10 IS, and my opinion hasn't changed since I reviewed that model. While I like the dial, it doesn't provide enough tactile feedback to match the control with the settings. For instance, when changing shutter speeds it doesn't feel like there's an equal amount of travel for each stop or indication when you've reached the next one.
I'm not thrilled about the placement of the review button; it's a bit too out of the way and I repeatedly forget where to find it. Canon seems to have darkened the silver plastic, though, which makes it a little easier to read the blue-on-silver labeling than on its predecessor.
I like the dedicated movie capture button, which works regardless of whether you've selected Movie on the mode dial. It's a bit too recessed though--probably to keep you from hitting it accidentally--with little travel, so it didn't always trigger when I pressed it.