Apple topped the smartphone list with a score of 791 out of 1000. LG ran second on 772, but also came first on the traditional handset list thanks to a score of 733.
Samsung put in a good showing with 759 for its smartphones, and Sony Ericsson was the runner up in the traditional stakes on 712.
The problem with this sort of research is that the weightings given to particular factors can skew the results.
For smartphones, the weightings were 30 percent for ease of operation, 22 percent operating system, 21 percent for features, 18 percent physical design, and 9 percent battery function.
Not surprisingly, Apple outscored its competitors on physical design - there wouldn't be too many arguments there. But it also achieved a top score for features, despite the iPhone's low-res, still-only camera.
That's because 'features' covers the "toggle or navigation wheel, touch screen, stylus, and calendar... [and] the quality of multimedia capabilities and quality of video."
And the low weighting given to battery function probably helped Apple too, as it (along with Motorola) got the lowest scores in this area.
Still, Apple's scores were "among the best" in all aspects except that one.
For regular phones, the weightings were 30 percent operation, 30 percent physical design, 20 percent features, and 20 percent battery function.
LG almost managed a clean sweep of "among the best" ratings, slipping to "better than most" for features. The only other manufacturer to achieve an "among the best" was Sony Ericsson for features - the highlight among otherwise "about average" ratings for its products.
If smartphone owners are more satisfied than those with regular handsets, why don't more of the latter group upgrade? Find out on page 2.
Not only did the top smartphones get higher satisfaction scores than regular phones, but their scores have risen considerably since the previous study published in November 2008.
"It is crucial, however, that manufacturers ensure these features are intuitive and that wireless carriers educate customers to maximize their wireless experience. While manufacturers continue to develop advanced features, they must also continue to provide a high-quality calling experience for their users," he added.
Although owners of traditional phones are aware of the benefits of smartphones, cost appears to be a barrier.
JD Power found that they spend an average of $US28 less per month, and $111 less upfront for the handset. Indeed, 42 percent of them received a free phone after allowing for rebates and discounts.
"Many owners of traditional handsets do not believe that the service cost associated with owning a smartphone is justified, as they indicate they would not take full advantage of the advanced features," said Parsons.
"Given the current economic climate, consumers are very aware of the extra cost associated with owning a smartphone that they may not use for more than basic calling and texting."