Luc,

I'm  little short on time, so I won't try and address everything you asked, but you did ask one thing I'll respond to.  You said I would guess that they are more profitable, is it a fair statement that applies everywhere or not necessarily. How are they yield wise are they equivalent?

The quick answer is for most farmers in most parts of the US the total cost of operation for RR beans (when you include herbicides, labor, etc) is pretty close to or possibly cheaper than conventonal beans.  The slightly abstract part is the value of weed free beans.  One or two applications of glyphosate (the active ingredient in Roundup) will give me a cleaner field than I could ever accomplish with a conventional program.

There is probably plot data to show conventionals out yield RR Ready, but in the real world wth real weed pressure I doubt it is a statistically justifiable position.