I've only had it for one day, but here are my impressions so far:
I love having the long end of the zoom. Makes all the difference for wildlife.
The viewfinder is digital, not optical. The viewfinder images are rather poor and you can't tell anything about focus or color. On the up side, the viewfinder shows all kinds of useful information, such as the current zoom setting, which an optical viewfinder wouldn't offer (the LCD display on the back also shows this info, but it's frequently unreadable outdoors).
It's rather poor at focusing, especially in dim light, where it can't focus at all in situations where my C-2020 would have had no problem. Even in bright light, it takes forever to focus -- I missed quite a few bird shots because the camera insisted on focusing all the way out, then all the way in, then finally back out to infinity where the bird was. Infuriating! The camera has a "My Mode" setting; if I could get it to remember a "My Mode" where the focus was locked on manual at infinity, that would solve the problem (animals are almost always at infinity), but as far as I can tell, "My Mode" lets me specify manual focus but then doesn't let me specify where to set the focus; not only that, but it also isn't in a mode where I can either see or change the focus, so I still have to do the "hold the button and wait two seconds to get into MF mode" even though I'm supposedly already there. I really hope there turns out to be a faster way! (Of course, for something like a hawk circling overhead, I can put it into MF and focus to infinity by hand, then just leave it there while I shoot, as long as I don't shoot anything else in between hawk shots.)
Update from second day: setting it to spot-focus mode does help with focusing speed. Setting to infinity isn't much help -- at f/3.5 the lens is still fast enough that flying birds aren't necessarily at infinity focus.
"My Mode" doesn't let you specify no-flash, but that's okay: because a nice feature of this camera is that the flash is retracted by default, and the camera won't flash unless you pop the flash open (with a dedicated button on top of the camera). So it's very easy to tell when flash is enabled, and very easy to turn flash on and off -- no cumbersome cycling through five or six flash modes as on earlier cameras.
The camera offers an optional "Seamless zoom" through its 10x optical range then into its 3x digital range. The viewfinder Since I usually shoot at 1600x1200, less than its 3.2Mp maximum resolution, that means there are CCD pixels to spare, and the first bit of the digital zoom should actually use the CCD rather than interpolating. I wish it had a mode for "seamless zoom up through what the CCD can do, but don't interpolate" but alas, it doesn't.
The EXIF is strange regarding focal length. Rather than indicate that digital zoom is used, it pretends that digital zoom is real, and multiplies the focal length listed in the EXIF. Too bad. Also, I've noticed that for some shots where I thought I was using only optical zoom, the focal length listed in the EXIF is greater than the actual lens max of 59mm -- which means that in seamless zoom mode, it isn't as easy as you might hope to stay out of the digital range.
I still need to shoot some side-by-side images with the C-730 and my C-2020 (an excellent camera with an excellent lens, but I've always been dissatisfied with its zoom range). I rather suspect that the extra glass in the 730 will cause it to show less intense colors and more problems such as flare, but if the difference is fairly small, I'm willing to accept the trade-off to get the zoom range.
With the USB cable, the camera shows up as a generic usb-storage device and works fine with Linux, plug and play. Woohoo! I know nothing about the Windows software that comes with the camera.
The batteries that come with the camera are non-rechargeable. That seems a bit chintzy. Fortunately it can take double-A's so my NiMH batteries will work. I'll do the same thing I did with the C2020: carry a spare set in the camera case, switch when I get a low-battery warning, then put the used set in the charger when I get home. The C2020 had excellent battery life (a set of NiMH would last for about two 64M cards in normal use); I expect the 730 won't be quite as good, because of the electronic viewfinder and the longer range zoom/focus, but we'll see.