IB Smart or not?

Any opinions about whether it is better to route orders through IBs SMART or directly to the principle exchange of listing? Advantages / disadvantages of both?

TrendBert

 

They charge less if you route smart via the API.

 

I use both
Smart from 930 - 4
Smart plus the other exchanges during premarket and after close as if you place working limit orders on smart you will often get a flow through or a part fill.
Also lets you know what the true best prices are as smart is not always the best.

w

 

I think smart is ok for the usual order routing.. for real direct access trading IB is not the best option anyway