Although the Action might be a little complicated for beginner users of PS, once it is set up, working with great flexibility, options and control on B+W's is a cinch (as apposed to convoluted). Setting up the action should take maybe 5 minutes. Here is a simple but powerful formula:
Get the color raw image to look great in color, in ACR with your preferred white balance (it can be relatively saturated).
Once the image is brought into PS (in 16 bit) start recording the Action (and maybe assign it an F-Key) by going to Windows/Actions/New Action.
The B+W Action:
With your RGB image open in PS, go to Channels palette, Copy the Blue channel (select all, CTRL A, copy, CTRL C).
Click on the composite (RGB) channel (the top one) there before going back to your layers pallet.
Open a New Document (once you do this just click "OK" and it will be the right size and color space) and then paste (CTRL V) the Blue channel there, name it in the layers palette "Blue" (by double clicking on the name) and then flatten the layer (Layer/Flatten) to get rid of the extra canvas underneath the layer.
Go back to the original RGB image and do the same thing for the Green Channel (select all, then copy the green channel).
Go back to the New Document and paste the Green Chanel into the document on top of the Blue one, name it and don't flatten.
Go back to the original RGB image and do the same thing for the Red Chanel (copy the Red Chanel).
Go back to the New Document and paste the Red Chanel into the document on top of the Green one, name it, don't flatten.
Go back to the Original, and convert the color space to LAB (Image/Mode/LAB).
Click on the L-Chanel (in the Channels Pallet) and select all, and copy.
Go back to the New Document and paste the LAB, L -Chanel into the document on top of the Red one, name it and don't flatten. (yes the L Chanel will convert to your preferred RGB space with no quality loss or significant noticeable change).
Name the top Chanel L.
Stop recording the Action.
You are done.
Now you have the R, the G, the B, and the L (and potentially anything else you want) sitting there with the press of one simple button as Layers (and all the power that goes along with that).
Now all you have to do is enjoy looking at the different qualities of each channel (clicking on and off each eyeballs in the Layers pallet) figure out an opacity mix you like the most (or even just work with one). As previously mentioned, you now can also use layer Blend Modes, and the Layer Style "Blend If" sliders for unprecedented power, control and options for your B+W's (also blending of layers by standard erasing, or making selections and feathering and deleting or graduated erasing with a mask and gradient...). Once you get the B+W image just the way you like it most (by working simply or more powerfully) Flatten the image and then do additional contrast work (if you want, both globally and locally).
If you keep a color layer in the mix (at the bottom of your layer stack) you could also add b&w adjustment layers to the mix or even a channel mixer layer if you so desire.
There are ways to make this even more powerful, but for most people this is plenty and can take their B+W's into a new stratospheric realm.
BTW, this is the general technique I teach my B+W PS students, bypassing the basic Channel mixer and such. So far it has worked wonders for them.