Belgian Golden Strong Ale - FG concerns

On 11/3 I brewed an AG, 6-gal batch of Belgian Golden Strong Ale. Here's the recipe that I used (based on a recipe from Jamil Zainasheff):

12.0*lb Pilsen Malt (I used Belgian Pilsner malt from Castle)
3*lb White Table Sugar (Sucrose)
3.0*oz Czech Saaz (3.0%AA) - 90*minutes
White Labs WLP570 Belgian Golden Ale


As per Jamil's recommendation, I mashed at about 149ºF and hit my OG dead-on (1.075). After a 90-minute boil and chilling I pitched a generous amount of WLP570 from a 1-gal starter (after pouring off most of the starter wort). As expected, the fermentation took off like gang-busters at ~64ºF and I transferred to a secondary fermenter on 11/16. It has been sitting undisturbed until today (12/5). I took a gravity reading and was shocked to see it at 1.004! That's almost 95% attenuation! I was expecting (hoping) it would end up at about 1.008. It tastes pretty good with no sign of infection whatsoever but is quite dry and there is a bit of fusel alcohol "hotness" to it that I am not used to tasting in commercial versions of the style (e.g. Duvel). I intend to let it sit in secondary for at least another two weeks before priming and bottling.

I'm wondering if attenuations this high are normal with this style and if the fusel alcohol hotness will diminish a bit as the batch matures. Before the brewday, I had done some reading about other people's experiences brewing this style and, based on what I had read, was anticipating problems with under-attenuation rather than over. Perhaps I over-corrected? Would I have maybe been better off mashing a few degrees higher?

Any thoughts are appreciated.

1.004 seems reasonable. You have 3 lbs of table sugar in there; that's a lot. Remember table sugar will ferment more than 100% (if you just fermented table sugar .... say 1.060, it will end up somewhere around 0.990).

You have almost a third of your fermentables as sugar, so lets imagine you fermented the sugar and malt separately. If 2 gallons of 1.069 sugar solution (3 lbs in 2 gallons = 1.069) ferments down to 0.990, then 4 gallons of 1.078 malt solution would need to go to about 1.011 (or about 86% effective attenuation) to have an average FG of 1.004.

I'm not saying these numbers are precise, but trying to show how the large amount of sugar can considerably lower the FG of a beer.