Like any area there is a variation in desirability (although it is of course subjective). Healdsburg is a small town and proximity to the plaza is considered very desirable by many, while more of a country feel (with or without acreage) is the choice of some. The busy-ness of the street is a factor along with the proximity of businesses or apartment buildings. I was just explaining this to a client last weekend as we considered a number of homes. While they could have afforded a very nice home within 2 blocks of the plaza, they chose something a litle further out in a quieter area. Other clients of mine who have bought in Healdsburg most definitely wanted to be an easy walk from the plaza. As one client put it, he wanted to be able to walk home after a fabulous dinner at Cyrus, and now he can.
Literally block by block there are variations in style and quality of homes so it takes someone familiar with the area to introduce you to your options. Whether the property has a 1 acre hobby vineyard or not is also a function of how much of a country feel the buyer wants. Many people who move to the wine country like the idea of a hobby vineyard. Many of my clients who buy property with smaller lots will plant a few vines as a landscaping feature just for fun, and make some homemade wine.
Also, the nature of the vineyard matters. Is it old chardonnay? What kind of root stock? Is it irrigated? Has it been well maintained? I wouldn't consider it a liability per se unless it was at the point of needing to be ripped out. Many new or part time residents in Healdsburg or in other parts of Sonoma County like the idea of a small vineyard, but might want to have someone else manage it, either in trade for part of the wine produced, or for a fee. I have neighbors that manage my small vineyard and we split the proceeds, in this case (so to speak) a dozen or so cases of zinfandel.
I hope this is somewhat helpful and I recommend you work with an agent knowledgeable in the area so that you can see what makes sense for you. There is a little foreclosure home on the market with its own hobby vineyard at a very good price.