Great question, Daniel.
First, what Rahsaan said.
But your question opens up all sorts of cascading questions, issues, and responses. Which is what makes it a great question: because it leads to so many other things.
A danger of early bud set (beyond what Rahsaan said already) is that you may still be getting those Spring showers, and too much water at this time can have some serious consequences. For instance, if you have an exceptionally long wet/cold Spring it could retard the shoot development in the early stages, which may have an effect later on in the season.
Plus, of course, with more moisture you always fun a chance of fungus mold proliferating, and that's never a good thing.
But it's so much more than just early flowering, Daniel. If you're attempting to compare different sides of the mountain (from a wine grower point of view), you have to consider the type of soil in each place (how porous, how good is the drainage, will the soild stay wet for long periods, will you have to irrigate), the prevailing winds and the force of those winds, the amount of moisture (or lack thereof; one side might get all the rain, the other might be in a rain shadow), the angle of the slope, which way the slope faces, the height of the slope, and the relative points of humidty at different places on the slope. How much sunlight does the slope get during the day? And what's the arc of sunlight on the slope during the day. Are there 'cold pockets' or 'hot pockets' in the vineyard?
And are the appropriate varieties planted in the right areas? (I have a friend who has a three acre vineyard up in the mountains. Because of the way the vineyard sits, they have a problem every year with the Merlot being susceptible to freezing, simply because of where it is. So they either have to avoid that place, or graft over another variety that can handle the cold better. Sometimes from one row to another will make a significant difference.)
You won't readily see it when you look at a vineyard, but if it is a good vineyard the grower has paid a lot of attention to selecting the right clone of a variety, as well as what rootstock it is planted on (different rootstocks have different vigor in different soils).
There's more....so much more. But for me that's part of what makes wine interesting, Daniel. I sure don't invest this much interest in Coca Cola or Kool-Aid. :^)