jeffh said:If that's true, then my objection changes from "It'll totally change the balance of everything" to "what's the point? Oh, and by the way, it will still change the balance of more things than I suspect you realize".
I don't think it'll really upset balance all that much: it /does/ make ability scores potentialy lower, especially the higher level you go, but even then most characters benefit from more than one stat being high. If your Str can't go above 18, you'll probably be happy upping your Con with your stat boost: and while I've not played especially high level, I do know that even my spell-caster players ponder exactly where to put each stat boost. Especially if you're using normal point buy, the chances are it would take you quite a while to reach beyond 18 anyway.
As for if it would actually make a huge difference: that depends on a few other factors. If purchasing items is more complex than saying "I buy a heaband of intellect +4, here's the GP", then it might become a bigger deal. Sure, most high level characters have Tomes, Wishes, Headbands, Gloves, Belts and suchlike boosting their stats, but the availability of those can vary a lot depending on your DM: and if your DM makes the higher boosts harder to buy and requires crafting, questing, etc to get them, then it might be a bigger deal.
Also, if you wanted to play more encounters where magic items can't always help (villains would logically use anti-magic fields to deal with the PC party known for it's impressive gear, or perhaps a certain plane might have odd effects on some magic items) then it might play a bigger factor. When Stormgud the Barbarian loses all his magical gear, some people might prefer that be "only human" no matter how high level he is: rather than, say, walking around with a natural strength of 22.
It's definatly a harking back to older edition concepts that plenty of people aren't fond of: so it's no wonder quite a few people have come on board to say, "That sounds utterly dire". But if you wanted to play a more, for want of a better word, "realistic" game, then it might be one such step to take. The kind of levels you'd need to get at for it to be a huge stumbling block (basically around level 30, by which time a standard point buy would have at least two of his best stats maxed out) would not be the sort of levels people wanting this rule would be wanting to play to, nor would they be likely using stat-generation systems that turn up paticualrly huge stats.
Of course, it might still be quicker to just play AD&D instead. ;-)