Machinist Skill Speed

[MrCookTM]

Det and crit increases dmg on all skills, even the Dot ticks. SS increases dmg on DoT ticks.

So even if SS increased DoT dmg more than crit + det, you still get more dmg increase to other places along side the lesser increase to DoT ticks. So from that perspective I'd say crit + det beats SS on any class (excluding "soft cap" for SS to get 1 extra GCD out during certain skills for example Warrior + berserk)

If mch had say 3-4 DoT skills, it could possibly be different case. But with only 1 I don't belive SS being better choise considering dmg output

Even if mch had 4 dots it wouldn't change. Take a look at smn, the job gets the most out of the SS dot dmg increase out of all the jobs, +SS affects pet attack speed, and it's still smn's lowest weighted stat.