I figure they're about 3:1. A round-trip economy air ticket in the US takes 25,000 AA miles or 85,000 HH points. Granted, that's not quite a fair comparison either, because AA points are only good on AA and partner flights, you might(?) be able to get an award from Hilton under conditions where you'd have to use a higher-mileage "AAnytime" AA award, and the numbers vary for different award types, but it's indicative of the ratio.

Personally, I find airline miles more useful because they can be used for high-leverage awards like international upgrades and no-Saturday-night-stay flights, and friends and relatives seem to appreciate free flights more than free hotel rooms, but it really depends on your own priorities.