Hardest and longest withdrawal is definitely benzos. But it's the easiest thing for me to stay far away from - because I would NEVER again willingly put myself in any position to have to face that hell again. I would literally choose death if told my only options were to be whacked out on benzos and live, or take a bullet.
Don't get me wrong, the booze withdrawals I've had have almost killed me 3 separate times - critical condition, seizures, DT's, the whole nine yards. But withdrawing from benzos I came dangerously close to killing myself at least half a dozen times. In retrospect now I truly believe my life was in more danger when I was mid-withdrawal from benzos - because the thoughts steamrolling through my head were darker and scarier than the blackest nights I've ever faced after a drunk, in ICU, hooked up to machines and stitched up from some bar brawl or self inflicted agony.
Throughout my entire adult life, even now (by the grace of God) having some quality sober time, I still can't stop frikin smoking. That just frikin bugs me to no end. I'd say for staying quit it's between alcohol and smoking for me - and cigarettes still have me big time. Benzos? Easiest thing in the world to stay away from - when I see a benzo script being filled at the local pharmacy I run away as if looking at an open vile of flesh eating bacteria.
BD777, that medic alert bracelet is an excellent thought, I'm getting one for sure.