Pros:
Much improved trip time estimates
Better routing choices than previous TomTom models
Interface customization options
Cons:
Hard to see screen in bright light
No route optimization
TeleAtlas map accuracy (at least in Florida)
Inability to route to off-road locations
Operating System stability
I've had the 930 since the end of April, running it side by side with a Garmin 760. Overall, it's been a fine performer. But it's also pretty much a 920 with only one real updated feature. . . IQRoutes. TomTom added (via navcore8) historical speed data to the TeleAtlas mapset, greatly improving not only it's estimated trip times but it's routing decisions. Whereas TomTom devices have been among the poorest in drivetime estimates, the 930 is now pretty much dead on for most trips. In fact, my Garmin, which has always had excellent drive time accuracy, now is matched and even sometimes bettered by the 930, depending on time of day. Both units can be trusted in this regard. Routing is also improved. During rush hour, if the TomTom 930 recommends a different route than my nuvi, I tend to go with the TomTom. In the evenings, or at light traffic times, the 760 may be a bit better, tho not always. In fact the 930 and Garmin 760 will now frequently recommend nearly the same route. This is really the only step up feature from the 920 for all practical purposes. The other two touted features, Active Lane Guidance and Static Interchange Images, will rarely, if ever, be seen by most users. In 6 weeks of driving in Central Florida I've seen ALG perhaps three times and Static images never. Not even once. The only users who seem to ever see them are in the countries densest metro areas: San Francisco, Chicago, New York, etc, and no frequency even there. So if these are the features that interest you, buy a TomTom 920 instead (or better yet a Navigon). The hardware, features and performance of the 920 and 930 are otherwise identical. For the current price difference between the 920 and 930, my recommendation is the 920. Just not yet enough difference to justify the extra $150-$200 price premium for the 930. Until IQRoutes takes time of day into consideration in it's route computions, the usefulness is still somewhat limited. Currently the options are three: Mon through Fri / Saturday / Sunday. No time of day or weekday option.
A couple of issues I have with this TomTom are system stability and the TeleAtlas maps. In Florida, at least, the TA map, while very detailed, is much more error-prone than the Navteq maps (used by several others, including Garmin, Google and Magellan). There are a lot of "imaginary" roads, some highways misdrawn, and others no longer existing or misnamed. The maps do appear to reflect many new road additions, but are slow to show corrections to existing roads. This level of error is not seen in my Navteq map, tho it too is far from perfect or all-inclusive.
My 930 has rebooted for no obvious reason on several occasions and required one system reset so far. In contrast I've never had to reset my 760 in nearly 8 months of use and can remember only one spontaneous reboot. The TomTom OS is suspect with regard to stability in my opinion. Speed limits data is seldom seen, unlike my 760 and Navteq's extensive speed limit displays. Map updates have also been somewhat problematic. The only other issues of note are listed at the top of the review, with the screen being the most apparent problem for most users. The Garmin 760 display is very bright with vivid colors and clean text, easily seen in my truck with the brightest sunshine. The TomTom 930 screen is sometimes nearly unreadable under the same conditions. Moving it off the windshield, using an optional vent mount for example, improves the viewing quite a lot.
Voices are very good, not quite the quality of the Garmin voices, but usually a little louder. Some limitations on enunciation , but not enough to cause an issue for most users. The included remote is more of a novelty than truly useful, IMO, as I can touch enter addresses faster than I can with voice entry and with less aggravation. It should be noted tho that the only way to move backwards in the menus is with the remote.
Overall, the 930 is a very good automotive gps, better than my 760 at some things, worse in others, but worthy of consideration, tho the 920 (or nuvi 7x0's) is a better value for the features.