While they're not the largest camcorders in their class, the HF S models are on the big side for consumer models--almost too big to fit in a roomy jacket pocket.
To one side of the lens Canon placed a new Custom dial, which looks, feels, and operates similarly to the control dial on Sony's prosumer models. You press the button to enable it, then use the dial to adjust whatever setting you've programmed it for--choices are exposure, focus, assist functions (70/100 IRE Zebra and peaking), mic level, and automatic gain control limit (0 to 18dB). I like it in the Sony and in here as well; it's a comfortable interface for adjusting options like exposure and focus, though I'm not fond of it for cycling through the Zebra and peaking options.
Big zoom switch
The zoom switch is large, with a very nice feel, and the mini accessory shoe cover slides back into the body.
Canon placed the mics on either side of the lens barrel rather than on top or bottom as is more typical. It doesn't seem to have an adverse effect on sound quality, however.
I'm not crazy about the feel of the various buttons on the LCD bezel; they're a bit too flush with the housing, making them hard to press, especially the playback controls.
Dual Shot mode
The Dual Shot mode is misleadingly named. It's actually the camcorders' full auto mode, not the Simultaneous Recording mode that allows for high-resolution still capture while shooting video.