I finished off the rebuild of my 2010 Cannondale Synapse with new wheels from ProWheelbuilder (H+Son Archetype, White T11, CX-Ray). The other big change was to go to a SRAM 12-32 cassette, which along with the standard compact crank now gives me almost as low a gear as on my other bike with the triple crank (34/32 vs. 30/27 on the triple). At my age and ability level, I need all the help I can get on the hills!
While I was at it, I replaced the white bar tape. There's nothing like unwrapping the old tape to see the contrast between the dirty part and the clean tape under the overlap! And yes, that is a Brooks saddle; works for me is all I'm going to say about it.
The weight results for the new wheels come out as follows, in grams (listed as F/R/Total):
Bare wheels w/rim tape: 729/902/1631
With cassette: 729/1219/1948
With Conti GP4000s and tubes: 1049/1559/2608
Comparing these with my previous Mavic Aksiums, they save about 410 grams. The 12-32 cassette is about 50g heavier than the Shimano 12-27, but then again it's mass close to the hub where it contributes a lot less to the moment of inertia than do the rims and tires. In that regard, both the rims and tires are lighter than the Aksiums.
Now as I write this just having come in from clearing another 6" of snow from my driveway in a 20mph wind at 10F, I can't even picture what it will be like to go out riding again, but I think I'm going to enjoy it when it happens!