personaly I have to say feruchemy would be far more useful to me I think then allomancy. reasons?
#1. I would love the ability to place a few unpleasant memories into a metalmind, then um, lose it somewhere
and be able to keep any memories I DONT want to lose forever.
#2. the storeing youth etc would be REALLY useful back in the days when I was younger. i.e. want to go out drinking and gambleing but only 16? no problem, store some youth and be older for a day.
nobody questions someone who looks 40... then when one gets old, but wants to go have some fun like you were young again, all that stored youth from being young could really come in handy.....
#3 storeing weight? ok cant underestimate the ability to get heavy, OR light at any moment. same with strength. store some, you want a mean punch, tap the strength right when you start punching, and tap stored weight. you want to jump high? strength + store weight = fun of flying without the need to carry coins... st
Storing strength. somewhat overrated probobly. but then probobly useful when one is trying to fall asleep and rather wound up (provided you stored mental speed as well, should be an easy way to fall asleep)
#4 storing warmth... ok, ever been way to hot? no problem. too cold? no problem, always comfortable. easily one of the best abilities
#5 storeing health. refer to comments about when one is young and in school, and wants to call in sick.......... *cough cough* and same for work when you are older. then access the stored health whenever you need it. both storing and tapping are still quite useful
#6 storeing senses. um, I cant count the number of times I wished to get rid of my sense of smell or taste. for a little while... hard to beat this one. probobly useful sometime to tap it. but far more useful to store it imho.
#7 storeing mental speed. would be useful anytime I wanted to be a little more numb to listening to something I really wouldnt be listening to, and dont care about. again, for more opportunity to store then need to tap. so again no shortage of power
overall virutaly any ability would be at LEAST as useful to store as to tap. leaving an easy and probobly neverending supply of power on demand
where as allomancy = weak once you run out of metals.
Loki