I can't attest to the relative merits of the different brands, but if you haven't done so already, you might have a look at MSC (mscdirect.com). They show offerings from Starrett (of course), but also from Mitutoyo and Fowler, as well as some generic "import" models.

Would you care to share your reasons for wanting a vernier model in particular? Desired measuring range? Inch/metric/both?