I came to US in 2000 May through ACE Technologies, in those days ACE had some good marketing people, I was placed with a direct client with no layers. But after 1 year my project got over and I was on bench for 2 months and due to the poor market condition they could not place me, I moved out into a permanant job.
I am not sure about how things are now, but I heard that desi consulting companies are not making good margins because of low billing rates and too many layers.
As long as you have a project, you are fine with ACE, they pay in time and operate as a standard company. I am not sure about Green Card processing though.
Good luck.