Flow offers a guarantee, in exchange for low pay and a long wait.

If you're very risk averse, go for flow.

If you have black marks, probably should do flow.

You can still apply OTS to other majors (and I think AA too) while you wait to flow.

If you're a go-getter, have great people skills, technical degree, or other resume items which make you stand out from the crowd you probably don't need flow, although there's always at least some risk of acquiring a black mark in training or on the line.