Welcome back, Chip.
As you've figured out, the clearnav is a step up from the GNII. A big advantage: no more pda to reboot, batteries to fail, software to reload, etc. Huge screen, updated software to the latest US contest rules, very intuitive user interface, easy to read in sunlight, actively supported by US based company. A necessity? No. A convenience? Yes. A $3k, er, "investment" as our Dear Leader likes to say? You betcha.
I find that the 302 vario -- quite a few used now -- is a noticeable improvement over the L nav, and the CN vario a noticeable improvement over that. Same questions and answers.
The other modern equipment is undoubtedly good too, this is just mine.
John Cochrane