The 123's are pretty easy provided they have not been left unmaintained over the years. I have 2 and a "R" model, pretty good runners. Canister stoves, I have gotten by with my MSR Pocket Rocket for 8 days on the small canister, boiling water at night. The MSR DragonFly simmers pretty well and if you have the funds to pick up off of eBay a BernieDawg DragonTamer cap, it will run very quiet and simmer unattended for quite awhile if you keep the steam from the pot in view. I have not used the Coleman "X" series, I have a good stock pile of Powermax canisters for them and now have the Xtreme and a Xpedition that I can try out this Fall. Last Labor Day on a trip with JimS, I observed that the morning coffee water was ready pretty.........dang...............quick. They should be neat to try. A canister stove off everyones radar is the Coleman Exponent F1, tons of btu's worth checking out, but discontinued.
Duane