I'm surprised, because you don't often hear that particular criticism of 2C-B. Mostly, people complain about nausea, or the fact that it burns very painfully when people insuflate it

Purity and accurate dosage is a function of your vendor. Buying 2C-B pills will be more dangerous, they are notoriously underdosed and should ideally be sent to a lab first, but at the very least spot-checked with a reagent test kit.

Duration is a subjective preference, I feel. LSD is nice, I like it very much, but I can understand than 12 hours uninterrupted is not something everyone can allocate in their schedule.