The results are mixed. Firstly, the Smoothee definitely improves the smoothness of the video. It's a lot more stable than if I hand hold the iPhone 4. On the other hand, the iPhone 4 on it's own is terrible; most modern video cameras with some sort of optical video stabilization will do a much better job than the iPhone 4.
Is optical image stabilization on a consumer video camera as good as the iPhone 4 with the Steadicam? I think it depends on what you are doing. If you're walking, the Steadicam is better - though not always perfect - but if you're stationary and just aiming the camera at different things, it's a toss-up. In some cases the iPhone 4 did better, and in some cases it was worse.
Definitely, the more time I spent with the Smoothee, the better I became; so maybe another few days of solid work with it and a reshoot would produce even better results. If nothing else, it will have trained me to avoid problem moves.
Moving past the Smoothee, this exercise reminded me that shooting with the iPhone 4 is a bit of a mixed bag.
iPhone Shooting Tips
Check your free space: If you're like me and fill up your iPhone with your iTunes library, you're going to have to take off some material just to make sure there's enough free space for what you're recording.
Airplane Mode: Put the iPhone in Airplane mode; it will save power and stop any calls from interrupting you!
Restart Your iPhone: I recommend completely restarting the iPhone before any really important day's shooting. I've found that the Camera app has a tendency to do unexpected things; not switch from still to video mode, or freeze during startup, or not start recording immediately. This, of course, only happens when something important is going on!
Watch exposure: the auto mode in the Camera app is the biggest pain. You either need to be careful about lighting conditions; or use another app! (see below.)
The thing that disappoints me the most about shooting with the iPhone is that while it can record very good quality video, it only does that IF the auto-exposure is working right. And whether it's working right depends upon lighting, subject, and what you tell it to focus on.
But if you are unlucky (which I found in my situation, was at least 75% of the time) you'll get a lot of wildly blown out video.
Now you can click on the iPhone 4 screen to get it to focus on a region of the image, and it will then adjust exposure based on that region. But pan the camera or have the subject move and the iPhone will recognize that the subject has gone, and will go back to fully automatic mode. One solution is to repress the screen during shooting, but you can't do this on a Steadicam Smoothee and keep the camera from wobbling (and you might even have problems if it's on a tripod.)
Net result; lots of blown out video.
So what to do? Well, I did what I often do when faced with terribly exposed video; turn it to black & white and let people think it was a creative choice!
One last tip, I've come across the app "almost DSLR" which let's you lock exposure and focus on the iPhone camera while shooting video. It works, but I have found it very hard to work with; the screen is filled with options that are lightly masked over the screen, and are almost unreadable (the screen shot doesn't really show how hard it is to read - and click - those buttons.)
NotesOnVideo: Steadicam Smoothee Unboxing & Initial Impressions
iTunes: almost DSLR
B & H: Steadicam Smoothee for iPhone 4 [$179.95]
Amazon: Steadicam Smoothee for iPhone 3GS [$179.95]
B & H: Steadicam Flip Ultra Smoothee Mount [$24.95] - not yet shipping