IMO, the weight savings going from a silnylon solo tarp to cuben is over-rated, especially as a "first pass" strategy. If you do the math, a 6'x9' tarp is 6 sq yds of material. Going from a 1.3oz silnylon to 0.74oz cuben saves you 0.55oz per sq yd, or a total savings of 3.3oz for the tarp.
You could take one less pair of socks or underwear and a few less band-aids and get comparable savings.
I think going to cuben makes much more sense for larger shelters (you save 9oz for the Trailstar, for instance) or when you've already got your gearlist zeroed down and are now looking to optimize/upgrade each gear item.
FWIW, I have a 11-12lb base weight with a silnylon tarptent, a canister stove, a "real" sleeping bag (WM Ultralite), plus some luxuries like a Kindle, camera and even a trowel and toilet paper.



