"Mike" wrote in message
rectangular bench dogs where making the dog holes is simply a matter
of routering (or dadoing) some slots into one of the boards before
gluing up the top. I chose that route for my bench but I don't think
there's any huge advantage to either approach over the other.

There's always advantages and disadvantages to different types. A round
bench dog will turn in it's slot to flatly face whatever is pressed against
it. Square ones can't do that and maybe slightly more likely to leave an
impression on the wood butted up against it. I'm sure there's some
advantages to square dogs over round ones, but can't think of any right this
moment.