I moved from a Galaxy S to a Omnia 7 about a month ago and haven't looked back.
It's slick, there are some very nice apps available and Zune music is nothing short of amazing.
Every area it lacks in (esp. turn by turn navigation) is now due sometimes round Aug. with the Mango update, which also includes MSN Messenger integration, Twitter integration, Multi-Tasking, Bing Audio-Vision (think advanced Shazam), Visual Voicemail, Intergrated Bar Code reader, Stand Alone Podcast support (Podcasts use Zune on PC atm), SMS dictation, Hand Writing Support, IE 9 Mobile with HTML 5.
Also MS recently released a load of new API's for developers so we'll soon see Apps like Layar (confirmed) etc.