It's been a long time since I've posted much on this site, but I'll tell you my personal experiance...
I made a sugar wine about last March or April. It was just boiled water with enough plain old table sugar to make the hydrometer read about 12% ABV potential, and a teaspoon or so of nutrient. I pitched a smack pack of (of all things) the New Belgium Yeast that Wyeast had for a limited time last year. It had a tolerance of 12% I believe.
Then around Sep. I measured the SG and found it to have about 2% abv potential left. Since it had stabilized at that, I went ahead and bottled in 1 liter tequila bottles. I added 2 tablespoons of Raspberry Extract (that contained no sugar) to one of the bottles.
I tried a shot of the Raspberry bottle (about 10 min. after adding the raspberry extract) and while it had a pleasant raspberry taste, it had a very soapy taste. I'm guessing because I bottled right on top of the Star San foam.
A month or so later I tried it again, and it tasted great. I've noticed that some bottles have started to have some small bubbles (like in a bottle of soda water) coming to the top, but as of yet, non of them seem to have built up any real pressure (I open the caps every week or so to release the pressure, and only get a tiny poof of gas releasing so I'm not worried about bottle bombs).
I think that if I tried this with a higher tolerance yeast (IE. Pasteur, or another 18-19% yeast) I would get the same results but with more alcohol.
I will admit though, as I have not had much interest in brewing lately, I have not tried more than 1 or 2 shots of this stuff in a night, So I can't make any statements about hangovers the next morning.