A few notes here:
First, this is D&D not Hackmaster. There isn't a fireball spell at every level. Consequently when comparing spells of higher level vs. metamagic spells, there will amost ALWAYS be significant differences. Even the most apparently direct comparisons in the game (for instance, twinned fireball vs. delayed blast fireball) mask more subtle differences (the delayed blast fireball can be delayed, will burn right through a globe of invulnerability, and can't be negated by Spell Immunity for instance).
ruleslawyer said:
Except that I'll take negative energy damage + healing over easily-resistable elemental damage any day.
You're entitled to that view, but energy damage is not "easily resistable" at level 5. And, even with Electricity resist: 10, the empowered shocking grasp does twice as much damage as the vampiric touch. I'll grant that empowered shocking grasp has lost pretty much all of its luster by level 7, but that's true of most attack spells. After a while, lower level spell slots stop being effective offense. And other spells become possible that make the Empower Spell feat worth having. (Similarly, at level 1, you'll happily use weapon focus with a normal weapon but by level 20, you'll really want to be using it with a +5 Holy Evil Outsider Bane weapon of doom).
I disagree on this as well, for several reasons:
1) 1d4 negative levels affect the target's saves, which is the real point of enervation to begin with;
Myself, I find the attack and ability check penalty just as significant but the damage isn't to be overlooked. If there's a more direct comparison among 4th level spells, I'm happy to use it (and Empowered Scorching ray beats the energy orb spells too), but in the extremely generic category of "bad things to do to a single target with a 4th level slot and a ranged touch attack" empowered scorching ray seems like it will often be better than enervation. After all, why reduce an opponents saves and attacks when you can just kill him instead?
2) Scorching ray is traditionally seen as overpowered anyway, which blunts the effect of your comparison, AND
And why does it surprise you that the best spells to use metamagic on are the overpowered ones? Remember, we're comparing the metamagic spells to the most powerful spells of the next level anyway. If you want sucky spells with metamagic compared to sucky higher level spells, start a thread comparing empowered flaming sphere to shout. Of course the spells that, when metamagiced, compare to powerful higher level spells will be the powerful lower level spells.
3) We're back to talking about elemental damage vs. a non-elemental effect here. It's apples and oranges.
See stipulation 1 above. But it's still apples to apples if you're talking "nasty things with no save that I can do to an enemy with a 4th level slot and a ranged touch attack." And that's the way a wizard preparing spells has to look at it. It may not be as precise as we would like but both of them would be competing for the fourth level slot. And I can see a lot of cases where a wizard would rather have the empowered scorching ray.
Again, I see this more as a problem with scorching ray. More to the point, however, this is elemental damage (easily resistable) vs. the least resistable attack form in the books, AND you're using the absolute border case here; disintegrate scales WAY up from 11th level, whereas scorching ray does not.
Disintegrate scales up rather rapidly, but so do enemy fort saves. By the time it does 40d6 in theory, it will really do 5d6 95% of the time. About the only things disintegrate has going for it are its nonresistability (and, let's face it, a maximized scorching ray vs. fire resist 20 (unusually high for 3.5 monsters) is in the same ballpark as disintegrate vs. a successful save.
If you go into Complete Arcane, empowered force orb fares quite well against disintegrate too. (And maximized cold orb beats Polar Ray with one hand tied behind it's back at one level lower...then again, the ability to beat a decripit loser like Polar Ray is nothing to brag about).
Again with scorching ray. Can you use at least ONE other example of a suitable spell?
Sure. (If you read through the examples again, you'll see shocking grasp and fireball both discussed and Ray of Enfeeblement alluded to). But Scorching Ray is a convenient example because it's a good choice to metamagic throughout almost all of a character's career.
A brief primer on the spells to use metamagic on:
1. Magic missile (quicken, empower, twin), ray of enfeeblement (quicken, empower, split ray), all of the lesser orb spells (quicken, empower, twin, maximize), fist of stone (quicken--for odd builds like Eldritch Knight, Spellsword or Enlightened Fist), true strike (quicken, repeat), charm person (extend, still, silent, heighten)
2. Scorching ray (quicken, empower, maximize, twin), shatter (quicken--useful in some cases), false life (empower, extend), touch of idiocy (quicken), see invisibility (extend), Whirling Blade (quicken), detect thoughts (still and silent)
3. Fireball (empower, sculpt, maximize), lightning bolt (empower, sculpt, maximize), vampiric touch (empower, maximize, quicken), greater magic weapon (chain, extend), dispel magic (chaiin, repeat), suggestion (still and silent), heroism (extend), magic circle vs. alignment (extend)
4. Envervation (repeat, split ray, twin, empower, quicken), all of the energy orb spells (empower, maximize, quicken, repeat, twin), charm monster (still, silent, extend), dimensional anchor (quicken), assay resistance (chain--I think the target descriptor allows this)
5. Cone of cold (empower, sculpt, maximize), overland flight (extend), energy buffer (extend), firebrand (empower, maximize), wall of force (quicken), dominate person (still, silent, extend)
6. contingency (extend), chain lightning (empower, maximize), greater dispelling (sculpt, chain), disintegrate (empower--if you like it to begin with--I don't), anti magic field (sculpt)
7. delayed blast fireball (empower, sculpt), repulsion (sculpt)
I'm sure there are a lot more, but that's a pretty good list off the top of my head.
Otherwise, this sort of comparison tends to make me worry about scorching ray, NOT think metamagic is better. And again, we're back at apples and oranges. For a 9th-level spell, I have my choice of gate, time stop, and power word kill; for those options, is the ability to inflict 144 points of elemental damage to one target that requires a ranged touch attack worth it? Hardly.
Sure. I'm not saying that metamagic spells are always better than all spells of any given level. Otherwise everyone would always take metamagic feats. However, they do create spells that are better than a lot of the competing spells at any given level. (A twinned enervation, for instance, is strictly superior to energy drain since it takes an 8th level slot). And there are times when you might want to inflict 144 points of elemental damage with no save rather than (gate) blowing lots of xp and possibly placing yourself in an outsider's debt, (time stop) blowing a 9th level slot to cast a bunch of lower level spells from a limited selection more quickly, or (power word kill) accomplishing nothing because your enemy still has as many hit points as a 10th level fighter. If you want single target damage with a 9th level spell, you'll get better results with metamagic than with anything else.