I wouldn't stick questions like this in the recipe database... maybe next time in the forums section.
I think "dry" is caused by several sensations, and a low-FG beer can taste sweeter than a higher-FG beer if the latter is more carbonated, has heavier hopping, or astringent tannins and/or roasted dark malts. If the high-FG beer has only dextrins and glucans remaining, it will taste dry but thick; if the low-FG beer has glucose, maltose or lactose remaining, it will taste sweeter than a dextrinous, glucanous, saccharide-lacking beer.