I really like my Omnia with all the firmware flashes and mods.
Getting ready to flash it again, in the process of backing up all my stuff.
Been using a firmware that had Windows Mobile 6.5 on it, and the new one will have the latest features of WinMo6.5.
For what the phone can offer, I really like it. It has a lot of quirks, notably those quirks being mostly Windows Mobile quirks. Others might just be issues between WinMo and the phone's hardware.
Regardless, as much as I want to wait for WinMo 7 and its included Zune integration, along with powerful hardware, I think I'll be getting an Android device. Google is at the center of everything for me basically, so it will naturally be far better if everything Google is completely integrated right into my phone.
So far really liking the Motorola Droid. Great hardware (same as the Pre and essentially the same as the iPhone 3GS), and great form factor too. I like physical keyboards and have been missing it on the Omnia, but most phones with keyboards are bulky. The Droid is only a smidgen thicker than the iPhone 3GS. Otherwise basically the exact same, and offers a bigger screen to boot!

Far better app support than the Windows Mobile phones, and Android will quickly be getting a much larger install base as Android phones reach Verizon and essentially every carrier too, so the number of apps should sky rocket.
I do want to test drive a good Android phone to see if I can at least enjoy the overall interface.