I agree that gaining ability score boosts is increasing in power. You've convinced me.
Is gaining ability score boosts actually gaining abilities? (I am aware this sounds slightly silly, but bear with me.)
The abilities thing is still a red herring, because the entire MM thing is about "known" true dragons, not about all true dragons. Remember, it also talks about all True Dragons being Metallic or Chromatic too. It's simply not a definition.
But if you really want, the ability score boosts would give you the ability to take certain feats (Combat Expertise, for example), ability to cast higher levels of spells (if you're a caster), ability to better resist will based spells (remember, +2 to will saves is a feat, which is an Ex ability, so that counts too), ability to successfully land spells better, ability to succeed in tasks you otherwise couldn't (due to higher skill DCs, for example converting an indifferent person to helpful with diplomacy), and so on. Not that it matters much, because the MM entry still isn't a definition... in context, it's clearly talking about "known" True Dragons. This is the same shifting goal posts nonsense... just a few pages ago, I remember someone stating that no one was arguing for the MM definition and that Draconomicon was the source that mattered. Now suddenly we don't seem to care about Draconomicon, and the whole "primary source" bit is conveniently ignored. Give it a few pages and we'll be back to Draconomicon and ignoring everything else.
As for the 100feet thing, let's quote it again:
They range in length from several feet upon hatching to more than 100 feet after attaining the status of great wyrm. The size of a particular dragon varies according to age and variety.
This says quite clearly that while the size of a particular dragon varies according to age and variety, they will be more than 100 feet long after attaining great wyrm status. If you read that carefully, you'll see that it does expect you to be over 100 feet at that point... but the exact size depends on variety. But White Dragons never get anywhere near that.
And, you know, there's the metallic and chromatic thing, which should be even more obvious (most True Dragons are neither, MM says all of them are one or the other). Do I really have to post the entire MM description of known true dragons, and insert into it counter examples for pretty much every single part of that? Or can we just look at it and see that the MM is talking about what's commonly known about True Dragons, and clearly not giving a definition of any kind?
JaronK