No it's not![]()
Actually, i think it lends a lot to a developers desire and commitment to create a quality app for a non-shipping device.
1/4-1/2" in a button placement is going to make a huge difference between something flowing well and not. Something an on-screen simulator can't recreate for you. I've used some apps i often wonder if they actually USED IT on a device because it doesn't flow at all.
The Omni Group put some decent effort into a mock-up to test with until they get the real thing. It is going to make me look at their Apps more when they ship!