Local search and automated rating site Grayboxx announced a series of upgrades today, meant to enhance and expand the site as well as infuse some personal flavor (read: trust) to its core rating features.

As we’ve written the company’s “implicit reviews” pull together disparate information sources to rate local businesses. The upside is that its algorithms base quality scores on factors across many different categories and locales, alleviating a perennial challenge of generating content outside popular categories (i.e., restaurants in New York).

The downside, however, is that the automated nature of the ratings misses out on the personal flavor and context that has been behind a great deal of the growing popularity of user reviews in local search. Indeed, this “social local search” is an offshoot of the larger phenomenon of social networking. Its appeal is correspondingly grounded in a certain degree of social interaction, which automated scoring of businesses largely lacks. Add the fact that Grayboxx can’t reveal its secret sauce (how exactly it comes up with these ratings), and there can be misgivings about the veracity of the scores.

That’s where today’s announcement comes in. In addition to expanding the number of data sources aggregated to come up with its preference scoring, it has also infused user-generated review functionality. This will come in the form of aggregated reviews from Yelp and Citysearch, as well as an upcoming feature for users to write reviews directly into Grayboxx. This should help personalize the experience more so it doesn’t rely only on the merits of its automated ratings.

Today’s announcement also includes an official nationwide launch. Before this, the company has slowly rolled out in a number of mid-sized U.S. cities and attempted small, localized publicity events for each. Now that it is on a nationwide scale, it should be able to learn more about its own model and find out where it best “fits.” Founder Bob Chandra believes this niche is cities with populations from 100,000 to 1 million — those that the Yelps and Citysearchs of the world aren’t serving as well.

Overall, the company’s main goal going forward should be to continue to add sources of flavor and context to alleviate the challenge of a lack of personality in its core rating system. After a suggestion that video could represent an opportunity to add this “color,” Chandra replied that it could be in the site’s long-term future but nothing is on the books currently.

As we suggested in a past interview with Chandra, he’s also now thinking more seriously about licensing out the preference scoring to IYPs or other local search destinations that are interested in rating local businesses with more breadth. We’ll have to wait and see if prospective partners — and more importantly, users — bite on this promise.