There are a wide variety of them.
I am not a fan of the ones that repeatedly use Kickstarter as a form of advance sales and payment (first time - sure. After that, start acting like a company and not like a person working out of his garage). Also, as far as design goes, some of them tend to do pretty interesting things but the vast majority tend to churn out 44mm diver variants by the truckload (and often derivative designs at that, too).
Quite honestly, I'd rather buy a Seiko in the sub-$500 range than any microbrand I have seen so far. However, if there is a design that really speaks to you, by all means have at it. The watches themselves can be quite good value.