Wow, this is quite the fascinating thread and interesting from a "historical" context as well. It is neat to look back and see what people were thinking years ago.

The only thing I have to add that hasn't already been said is personal experience. I currently train in both Traditional Jujutsu (a derivative of Daito Ryu Aikijujutsu) and Brazilian Jiu-jitsu (specifically the Helio Gracie line with less emphasis on competition after becoming tired of the "thug mentality" I found at other variants of BJJ schools) and have found that the two ended up complimenting each other quite well. My arm bars amongst other things significantly improved training in TJJ and problems I faced going to the ground were easily solved with BJJ, even if it was something as simple as disengaging and standing back up.

The metaphor I use is of a toolbox and both TJJ and BJJ are different tools in my toolbox for different kinds of problems.