Originally Posted by
lufa1982
Excluding very duel oriented setups, most Engineers don't use any of profession lines, so how about that for answering your question.
Gadgeteer is broken for 6 years now
Demolitions is only useful for PvP-dueling due to absurdly short range on perks.
Creative Mind mods and perk actions are all hilariously useless.
Mechanic pet heal isn't bad, but iit doesn't actually enable you to solo anything that was already soloable without it.
PVM DD setups exclusively use group lines, general PvP setups use group with a bunch of General perks.