An excellent summary, Chris.
Firstly I should declare an interest here: I worked for Paramo in the early 90s and now have a business, FurTech, making similar products.
I don't run quite as hot as Chris and find that I can use these systems over quite a wide range of temperatures. For example the Alta trousers were my only leg wear (except for shorts) on a summer crossing of the Haute Route a few years ago. Temperatures probably ranged from 30C to -5C. I find that the systems temperature flexibility, due to its breathability and venting options, to be one of it's greatest strengths (along with drying quickly). On that trip I carried a sack with kit for me and my wife, which many times included my Paramo garments and her's.
I'm not saying there aren't lighter systems, but weight can't be viewed in isolation without factoring in all those other aspects of performance. However, I did a comparison of weights some time ago, inspired by one of Chris's articles that can be seen here: http://furtech.typepad.com/furtech_used_for/2007/04/furtech_for_bac.html
Finally I'd just like to point out that the dry clime system is very different, because the lining is hydrophilic, constructed differently and designed to wick. The pump liner design is hydrophobic and is almost the opposite knitted construction.
For more information on breathability and drying please use this link: http://furtech.typepad.com/furtech/2006/11/phases_of_breat.html
Best regards, Andy Davison.