Ive seen alot of posts surrounding both the Tocco, Iphone but not much on the Omnia, Basically the big brother to the Tocco. Just after some feedback from other members, Im not all sold by either Iphone or omnia.
Reasons for iphone, No bluetooth stereo support, limited media codec support, no native video capture, GPS is still limited unless a 3rd party offer a better navigation package than google maps.
As for the omnia, Its run Windows Mobile 6.1 which i havent used myself but used other versions and it doesnt seem to get great reviews, With no item such as App store i imagine apps and widgets will come now and again but nothing like apples level of offerings, functionality i dont imagine this comes anywhere near the iphone same goes for usability.
Things that do make the Omnia interesting 5Mpix autofocus, Video capture, DivX support, Upgradable SD upto 8Gbps although people report larger can be used.http://www.gsmarena.com/samsung_i900_omnia_announced_live_pics_inside-news-519.php