That sounds a bit contradictory. First you state you like harder mechanics for the sake of being harder because that's where you get your enjoyment. Then you say you do it for a marginal gain (500% harder for 1% more damage). It sounds like you wouldn't do it if there was -no- gain.
So that leaves me to wonder: Do you like min-maxing, or do you like difficult mechanics? Let's say every talent on the Mana Tap row does the exact same amount of damage in every scenario (hypothetically). Would you still take Mana Tap over the other two? If you wouldn't, you don't in fact like the mechanics, you just like high damage. Or let's reverse said scenario; if the passive option does more damage than Mana Tap, would you take Mana Tap or the passive?
Personally I'd only take Mana Tap if it was substantially better than the other options (which is all tuning anyway and thus not relevant yet). If it would be a marginal gain I'm staying well away from it even if I generally prefer more complex mechanics. Maintenance Buffs are just terrible gameplay in my opinion. There's nothing hard or challenging about playing with maintenance buffs, it just gives you another tedious weakaura to stare at every once in a while.