It’s a bit of a messy issue I think, and variations in labelling don’t help. If you’re able to talk to a winemaker, or better yet charm the enologist or a lab tech, and ask about their labeling practices, you may get more candid information than you expect. Some wineries make a point of labelling their wines accurately, while others basically subtract 1% from the lowest value they get and so significantly under-report. But you can’t exactly look up which ones do and which don’t, so “14.5%” on a label is, to the general consumer, a pretty useless number.
For those of us on this board, who spend a lot of time tasting, drinking, and learning about wine, I think the number on the bottle is even less significant, because many of us will be buying wines from wineries we have already researched, visited, or tasted from, or heard reliable information from a friend/fellow Berserker about the house style, which should reveal more about how likely we are to like a wine and find it balanced than the abv on the label.
I agree with what many have said above: that balance is more important than alcohol content. And I think what Otto was saying about location is also important. I tend to like my Sonoma County Zins at 14 to low 15s and generally find that lower-alcohol versions from the same area, even if well farmed and well made, are not to my taste, while higher alcohol contents there tend to be too hot for my palate. But I’ve had high-15s/low-16s Zins from Howell Mountain that tasted correct to me, even if they were a little potent for my day-to-day taste, and I’m sure there are areas that would produce good Zin below 14. There is so much more to ripeness and balance than sugar a.k.a. potential alcohol.
The one thing I do look for is <14% labelling on good Cabernet Sauvignon, because both my wife and I tend to like greener, fresher Cabs, and I have found that, in Napa and its surrounds, that legally defined boundary can be a good filter for improving our odds of finding what we’re looking for. I’ve tasted a lot of Cabernet Sauvignon with >15.5% alcohol and, though some of them have been mightily delicious, they have almost all been too alcoholic for me to really want to drink more than half a glass.