I have a set of Crests that weigh 1440 and a set of cheap Chinese carbon wheels that weigh 1420. The cheap Chinese carbon rims weighed ~370 and the Crests weighed ~380 so that is the difference but the difference in performance is night and day. The additional stiffness is very noticeable. The narrow ENVE's to which you must be refering weigh ~380 http://www.bikerumor.com/2011/11/30/env ... d-weighed/
but are only 18 mm wide inside. My wheels are much wider inside around 22 IIRC. The Enve wheels I was referring to as being heavier are the wider ones and they do weigh over 400 IIRC but are more comparable to the Crests and my cheap Chinese carbon rims being almost exactly the same width. Apples to apples.
I own a 2012 Sid and they are very light mine weighet 1630 but not as light as a lefty. The model of lefty makes a difference but the higher end carbon one with all adapters, etc ends up being almost exactly a pound lighter than my SID. I know people that have converted and that is the overall savings.
The SRAM wheelsets are the same as my wheels above. The aluminum wheels (Crest and Rise 60) can be as light as carbon wheels. The fact that my set is 20 grams lighter in carbon and SRAM's set is 50 grams heavier in carbon is neglibible. The performance difference is in the stiffness and responsiveness.
I stand by my original point that his bike is not heavy for what it is. I think anybody that has put in the effort to get weight off a bike will agree with me. Even after you spend mucho $ to get a light bike you will not enjoy it if you put 500 gram tires on it and depending on the type of riding you do your best tires could easily weigh 1500 grams instead of 1000 for the lightest tires.