I have to admit, I've gone back and forth on this subject. I really didn't see that much difference in prints with the more dilute developer except for extended development time. In the last couple of years I have "split the difference" and started using a dilution midway between the two.
I think if you are making a lot of prints, you may see earlier exhaustion of the developer and less uniform printing after a while. If you are not straining the developer, I really doubt you will notice the difference.
I usually use a dev. time approx 5-6 times the emergence time (the number of seconds it take for the first signs of the image to emerge). With RC paper this usually amounts to about 60 sec (an emergence time of about 10 sec). With FB is usually is more like 3-4 min. As I see the dev time turning much longer, I dump the stuff and start over (or if I have only a few prints left to do, add more concentrate).
Sam
