Here. In a nutshell, it wasn't nearly as stimulative as it could have been because too little of it was spent on consumption and investment.
I largely agree with this, but I think it glosses over two really important points:
1. At the zero lower bound, any deficit spending - even on transfers - is going to help monetary policy get traction than it would otherwise have, and that is a benefit.
2. Transfers go to certain types of people. Many, although not all, of these people are paycheck-to-paycheck types. Permanint income hypothesis concerns (which are legitimate, I think) apply much less to this group. The MPC of this crowd is quite high.
Still, a job is better than a transfer payment and it would have been nice to see more direct investment spending and employment (along with simply a bigger stimulus).