With the ability to do 360 divisions, I find it a very handy tool. I fitted mine with a block bolted to the base so I can simply drop it into the milling machine vise when I need to use it.
Its major drawback for me is the fact that it can't be conveniently mounted with the spindle axis vertical. This makes it more-or-less useless for jobs like drilling bolt hole circles on cylinder heads.
Get a set of collet blocks first. As Bob mentions, they're handier than a shirt pocket.
They can be used both horizontally or vertically but are limited to 2,3,4,6,8 divisions.
Fortunately, those numbers cover a majority of the work you're likely to encounter.
For a bit more flexibility than that provided by collet blocks, consider building a divider like my super collet block.
Mine allows for up to 24 divisions and the base can be easily clamped in the milling machine vise in both horizontal and vertical orientation. Given that you have a rotary table, you could drill it for any number of divisions that suits your work. Since multiple rows of indexing holes are possible, you can even have separate division circles tailored to your needs.