I was reading this link: https://www.askmehelpdesk.com/taxes/criteria-dual-status-filing-64475.html

And it seems it applies to me (J-1 since March, H-1B for the last 3 months of 2011).

So I could file now as a non resident, or wait a few weeks and file with dual status?
What would be the difference of choosing one over the other? Is there any advantage or disadvantage?

If I wait until the SPT before filing with dual-status then I will have missed the filing deadline for 2011 - so how do I indicate to IRS I have missed the deadline because I am waiting for SPT and thus avoid any fines for late filing?

Thanks

I do not think that there is any advantage is filing dual status tax return so file nonresident tax return.