My choice, when I want to carry a lantern, is the Snow Peak Gigapower Lantern without piezo ignition. With the glass globe, mine weighs 4.1 ounce (0.1 ounce more than the 4.0 ounce claimed by the manufacturer).
Perhaps switching the Snow Peak's glass globe out for the optional mesh globe would net an even lower lantern weight.
The piezo seems like something else to breakdown, and the mini-bic lighter that I carry anyway for quick flames to start a fire or light the stove (or light my pipe) serves as a "piezo" ignition for the lantern. Thus the bic, with its weight of less than .5 ounce even when full, serves as a multi-tasking tool.
As for reliability, have never had a bic fail to produce a flame so long as it has fuel. It may even be that, once its fuel supply is gone, the bic can still generate enough spark to light an alcohol stove or ignite tinder to start a fire, either of which can then provide the flame needed to light the lantern -- and the pipe.