I tried my hand at building my first wheel in order to swap out the rim on an old RX100 hub that is still in good shape. I tossed the old Matrix hard anodized rim (super narrow and hard to mount tires on, also poor braking surface) and replaced it with a wider Alex rim with a machined sidewall, both rims were double wall without eyelets. I also replaced the straight gauge spokes with butted DT Swiss spokes.
Once rid of the narrow rims, I switched from my Bontrager T1L 23mm tires to Specialized All Condition Armadillo Elites in 25mm.
I had weighed the original wheelset and tires when I first got the bike and figured that the wider rim and wider tires with puncture protection would drive up the weight. When I weighed the finished wheel I was shocked. It is now 45g lighter than it was with the narrow rim and non-punture resistant tire. I weighed the Bontrager T1 and the Specialized ACA Elite that is waiting to go on the front and the Specialized tires alone save 30g. Talk about having you cake and eating it too. (I suppose that is a bad analogy when we are talking about losing weight