I'm not sure I agree that Maximize is
always better than Empower Healing for a bard healer but here's the facts with a strict focus on healing.
Maximize effects all 'Cure' and 'Mass Cure' spells (including the least and lesser healing dragonmark) but does not affect any 'Heal' or 'Mass Heal' spells (including the greater healing dragonmark). It costs 25 extra sp's and doubles the effect.
Empower Healing effects all 'Cure' and 'Mass Cure' spells (including the least and lesser healing dragonmark) AND all 'Heal' and 'Mass Heal' spells (including the greater healing dragonmark). It costs 10 extra sp's and adds 50% to the effect.
If you run the numbers based on the assumptions of 40% amp from enhancements and 75% amp from a pot/clicky (easy to do on a bard) and using the
Guide - How boosts to healing stack you come up with some interesting numbers. The average non-crit cure serious wounds with no meta's running would be 61. with a cost of 20sp's that's about 3hp's healed per spell point. The average with empower healing running is 91 and with the cost of 30sp's is still around 3hp's healed per spell point. Maximize pushes that to 122 but the cost leaps to 45sp's which drives the efficiency down to 2.79 hp's/sp.
I could go on with all the numbers in the spreadsheet but it boils down this way for Bards:
1) Maximize is never more efficient than empower healing or no meta's. Not until Mass Cure Moderate does Maximize pull even in efficiency with Empower Healing. This is because our level 6 spells only cost 25sp's which is the cost of Maximize.
2) Maximize works out to 33% more healing than Empower Healing.
3) For the Mass Cures only, Maximize + Empower Healing is more efficient than either meta alone or no meta's. It's simply the best that you can do both in power of the heals and in efficiency.
4) If you're using Quicken then the break-even point between the healing efficiency actually moves up to Cure Critical. This means if you always run with Quicken on and only want to have one of them running then Maximize is your choice for most of the heals you'd be using.
5) If you're using Quicken then running both Maximize and Empower will almost always be the right choice - only Cure Light and Cure Moderate deviate at that point.
Finally, with regards to the dragonmarks (assuming the healing amp is the same) you'd be getting
30 x 9, 91 x 7, and 483 x 5 with Empower Healing for a total of 3,097 healing on average. You'd be getting 40 x 9, 122 x 7, and 322 x 5 with Maximize for a total of 2,824 healing on average. Now you can argue about which heals are more useful...that's going to depend a lot on who you're healing and what you're healing them through. But the empower healing provides more total healing from the dragonmarks - just less from the smaller ones. Obviously if you can fit both feats in then the dragonmarks benefit greatly - 51 x 9, 152 x 7, and 483 x 5 for 3938 healing.