Like the Canon Vixia HF10 and its nearly identical little brother, HF100, the SD9 records 1080i HD video at a full 1920x1080 resolution with a maximum 17Mbps bit rate. That's about 2 hours of best-quality video on a 16GB card. Like the Canons, it requires a Class 4 or better SDHC card for highest-quality recording.
Overall, performance is good. The SD9 adjusts exposure and focus relatively quickly, though like many consumer models focus slows as lights get low. The image stabilization works fairly well, but there's still some shake when zoomed out to the 10x maximum. The LCD seems to be worse than usual, however, seriously misrepresenting the white balance and exposure.
Video quality ranges from good to not-so-good. As you'd expect from a 3-CCD model, the SD9 renders very saturated colors. Exposures look good, but even when it underexposes to preserve highlights they still get blown out quite a bit. At its best--in good light--the video is a bit soft except when zoomed all the way in. In lower light, it looks either as if there's a film over the lens or simply overprocessed. Still photos are almost unusable; unsurprising given the low resolution of the individual sensors.
I based my quality judgments from viewing on the Sony KDL-46XBR4 HDTV and PC playback using InterVideo WinDVD; at review time, I had problems with the SD9's videos using virtually every editing package I tried. I subsequently succeeded with Ulead VideoStudio 11.5. You can read the details in my update to The hardware is willing, but the software is weak.
Though the Panasonic HDC-SD9 is a nice little camcorder, between the software issues--I'll update when they're resolved--and the inconsistent performance and video quality, I think you'll probably be happier in the long run by spending a little more for the competing Sony Handycam HDR-CX7 or one of the aforementioned Canon Vixia models.