I don't think there are any advantages or disadvantages.
My tomicogs look a bit more "raw", like some dude made then in his garage. In that respect, they fit well with the whole jerry rigged vibe of bolting a cog onto the rotor mount of a front hub. They function flawlessly however. There is no notable eccentricity, and mine show no signs of premature wear after several years of use. The teeth on the tomicog look really tall to me, although I haven't made any real measurements to confirm that, its just an impression. Taller teeth (if that really is the case) may reduce risk of derailment (?).
Bear in mind my tomicogs are a few years old and bought very shortly after they first became available. Perhaps the newer Tomicogs are more refined looking like the velosolo cogs, but in any case, they are well made cogs.