From Yale law professor Jonathan Macey in the WSJ:

On closer examination, it appears that what Congress really wants is to keep making the big bucks that come from trading on inside information but to trick those outside of the Beltway into believing they are doing something about this corruption. For one thing, the rules proposed for Capitol Hill are not like those that apply to the rest of us. Ours are so broad and vague that prosecutors enjoy almost unfettered discretion in deciding when and whom to prosecute.

Congress's rules would be clear and precise. And not too broad; in fact they are too narrow. For example, the proposed rules in the Stock bill are directed only at information related to pending legislation. It would appear that inside information obtained by a congressman during a regulatory briefing, or in another context unrelated to pending legislation, would not be covered.