This industry sucks.
Here's an article referenced by the 802.11n wikipedia article, supposedly justifying the claims that the maximum range of 802.11n is twice that of 802.11g. (125ft vs 230ft)
Here's the problem: they talk about "doubling the range" as meaning "the same speed at twice the distance or twice the speed at the same distance." Well, that sounds clever, but it's better for marketing than for reality. Basically, the article demonstrates that this is true by just showing how, at short range, you can get 144 Mbit/sec instead of 54 Mbit/sec (yay, more than double!) or at slightly longer range, your 802.11n connection degrates from 144 down to, say, 57, which is still more than 54. Therefore it meets both criteria for longer range!
Sigh. I'm pretty sure both of those are just examples of being faster - which everyone knows 802.11n is, and it certainly is in my tests.
But if my definition of range is, for the sake of argument, "the maximum distance from the AP where you can get near-zero user-visible packet loss and < 50ms latencies," then using that definition, I can't see how 802.11n is any better at all. It certainly isn't in any of my tests. Which makes sense, because both 802.11n and 802.11g just give up and use the same slow-speed encoding at longer ranges.
To their credit, the "approximate indoor range" column in wikipedia has a  despite the footnote pointing to this article. (The article, incidentally, never mentions a specific distance measurement. Which makes sense because it would immediately reveal that they're using a lying definition for "range.")
There. Just had to get that off my chest. I'm pretty sure that article - and a series of others from when 802.11n was released - is responsible for the persistent rumours that 802.11n has double the maximum range of 802.11g. It doesn't. Not even 10% more. Bah.
(Disclaimer: it's possible that chipset improvements from the same time period did improve range just by being better-made chips. This doesn't seem too likely though, since I have an ancient 802.11g Linksys router here that I also use for testing, and it certainly is no worse than the new ones in terms of maximum range.)