1.According to my lawyer,it is 30% on average.his case is 70% percent successful.I do not know wheather it is true or not.
2.The lawyer should work for you free if you have paid all the money for I140.
3.My case is reopened and approved in 43 days.I think you also try appeal to save time ,money and hard paper work.
4 you lose nothing if the appeal is denied.