First of all, I must point out that all of the calculations on Empowered spells are incorrect. A 10d6 fire ball double empowered does not equal an enhanced fire ball, as the damage is not in dice, but the final result is multiplied 1.5. This may seem nit-picky, but it is really more important with spells such as magic missile, various orb spells, chain lightning, ect. An otherwise average roll by multiple missile could end up on the bad side of the rounding down rule. Especially if each missile/orb is only rolling one dice each. You could enhance it five times, and if you roll a 1, you get a 1, as the base damage would be multiplied 1.5 for each time enhanced was applied. (By strict interpretation of the feat, this is the way to calculate it.)
Min/Mid/Max
10d6 = 10/30/60
10d6 x 1.5 = 15/~45/90
20d6 = 20/60/120
Like I said ,I know it's nit-picky.
Secondly, it is SOOOOO obvious by the ELH MM feats that were added that spellcasters are supposed to take the enhanced meta magic feat. Just take it three times, and then observe...
Fire ball
10d6
10d6 x 1.5 (empowered)
60 (maximized)
20d6 (enhanced)
SEE!!! A no brainer, must have combo. Since all of the above are now only at +1 spell slots, it is obvious that WotC meant for all spellcasters to take Enhanced MM, so as to make their new epic feats worth while. Duh!
* removes tounge from cheek*
Seriously, look at this, at +2 spell levels..
fire ball
10d6
10d6 x 1.5 twice, double enhanced.
60 + 10d6 x .5 (maximized and enhanced.)
30d6 (double enhanced)
If you take it six times, take a fresh look at intensify. Granted it would be a feat heavy investment, but at +1 spell level, your simple fire ball does 120, period. With enhance, at a +2 spell level, it does 240, period. Enhance spell, which is worthless, now allows you to use maximize and intensify, which are also worthless, to a whole new degree. Even if you don't want to spend that many feats on improving your damage, the above two examples are reasonably cost effective, and make empower the proverbial red headed step child.
Just like taking weapon focus in one weapon and improved crit in a different one is not a waste, just ineffective. Put them both on one weapon, and they become dangerous COMBINED, and they open the door to other feats on their trees.