No, I am certain that the fuel savings would not offset the extra weight of the Jetboil stove and pot (especially the standard pot with neoprene cozy and rubber lid), unless you were on a very long trip (Roman?). However, carrying less fuel cannisters is pleasing to me, and the Jetboil design is nice too.
Personally, I am waiting for someone (are you listening Jetboil?) to produce a titanium pot with an integral heat exchanger. Preferably in two sizes - a 700 mL boiling pot, and a 2L snow melting pot.
I found a cut down Jetboil PCS project posted recently, unfortunately I couldn't read it, but the weights were getting down to acceptable.
I have always wanted to try cutting the plastic off the base of a Jetboil PCS stove to see how much weight can be saved, but I fear I would end up with an unstable system that would require further mods.
Maybe I am the only one here still facinated with the Jetboil's heat exchanger, but a BPL MYOG article on an UL version would be great.