The SMART Act, introduced by Lamar Alexander (R-TN) and Chris Coons (D-DE), is better because it would create a new temporary visa for STEM graduates without eliminating any other green card categories.
Meanwhile, in the Senate, John Kerry (D-Mass.) and Richard Lugar (R-Ind.) have introduced the Startup Visa Act of 2011, which would reform our visa laws to take the entrepreneurial spirit of immigrants into account.