Tricky question! There are so many people out there who are new to corset wearing and frequently, they will lean towards an overbust. I'm not sure why, but my guess is because they can seem easier to wear (since you can wear it as you might any other top) and also because overbusts frequently feature more trim and pretty little details, making them quite difficult to resist.
In my personal opinion, there is no corset more versatile than either a standard steel boned or waist training underbust.
Don't get me wrong: I love overbusts and I love a pretty corset with the right details and trim! However, if you are only just beginning to wear corsets, chances are you are looking for something to wear beneath your outfits more-so than a show-stopping over-piece.
Wife, mother workaholic & entrepreneur. I do my best to bring you regular content via this blog, but as you can see from my archives, it doesn't always work out that way (see above, where I mention the whole "mother" thing).