I never really had a problem with upgrades even when I was a gold so haven't noticed much difference as a Plat.

The only thing I have noticed is different being a Platinum is that last night I was told I could guest 2 people into lounge at LHR and to quote the Lounge manager it is because you are a super duper uber tVIP...haha

I hit Plat in May this year and have just passed 170,000 miles since then and this morning as i was wasting an hour of my life circling above Dubai realised I fly far Emirates too much!