I've found that a lot of the generalizations made by different Iai teachers about iaiDO are aimed more at Seitei Iai than many of the koryu lines of Iai. Like you point out however, the name of the ryuha can tell you a lot more than the seemingly random classification words. I do find it odd that Jigen ryu would be considered particularly compatible with Aikido, since it's known for it's very direct powerful movements. To the untrained they often look a bit brutish. Perhaps it's a different line, but this is what most of the Jigen Ryu that I've seen looks:
http://www.youtube.com/watch?v=mq6lrpzVfm4
Update, looks like this is a smaller line that's quite different from most Jigen ryu:
http://www.youtube.com/watch?v=u6k0LJqIZp4