I shoot Nikons, d1x, d100 and d70 and I use Bibble http://www.bibblelabs.com/
for all my shoots. I'm selling the d100 with two lens, any takers? It has the abiity to batch process the huge amounts I shoot at times really fast and the B&W conversion is simple. Run the saturation to zero and adjust the RGB sliders to get the effect you want. A million years ago when I shot film i used a green filter to get skin tones just right. Using Bibble and the "G" slider I can pump it up or down after desaturation and get the B&W effect down fast and easy. Copy those settings to all you want to convert that way and bam! You're done!
I'm all about workflow whether it be B&W or color...
I will say there is no one tool for all the jobs. I tell this story a lot. Me Da was a carpenter. He had about 25 different hammers form 10 pound sledge to 1 ounce tack...use the right hammer for the job!
I use Fred Miranda's plugin at times for some that just need that feel. I also have some actions I made to get me through at times. Again, it depends on the image and of course where my head is at that time and place.
Pull out an image you haven't seen for over a year and just let your self go with it. I'll wager you come uip with a different image than you did the first time.
Bibble is a real work horse though for batching!
Just an opinion mind you...