I recently picked up Concrete Limiter and using it in Sonar X3 Studio.  It's a great module for the ProChannel, and I like to use it on my master bus as the final piece of the chain.  I'm one of those producers that, if I'm doing one song at a time, I prefer to do my mastering in the same session as the tracking/mixing.  So, my master bus usually looks like: ProChannel in pre-fx mode with EQ, and Bus Compressor.  Then in the FX bin, sometimes I add the Sonitus Multiband Compressor and sometimes a stereo widener.
 
Before I got Concrete Limiter, I put Boost 11 in the FX bin as the last plug-in to set the final volume and limiting.
 
Now that I'm using Concrete Limiter, because it only works in the PC, it ends up going before the fx-bin, which doesn't make any sense.  The chain ends up being PC EQ -->  PC Compressor --> Concrete Limiter --> Multiband --> Widener
 
So now I'm creating a "Sub-Master" bus with all the processing except limiting.  Then it goes to a "Master" bus that only has the Concrete Limiter on it.
 
I wish Concrete Limiter could also be used an FX-bin plug-in.  Then I wouldn't have to create an extra bus.
 
Anyone else encountered this issue and have a better solution?
 
Thanks!
 
Neel

How about using the PC post FX bin? Also you have the option of inserting FX chains anywhere in the PC. 

Yeah, I though of using the PC post-fx, but I prefer the PC EQ and Bus Compressor first.  But I never used FX Chains before - that seems like a great workaround.  I'm assuming I can put whatever plugs I want in an FX Chain, right?

Yes, no need to use fx bins whatsoever.