Great as a FileMaker Server. Even for heavy duty use (one investment client has more than a decade of transactions that gets processor-intensive reporting done monthly) they work great.
Latest iMacs offer more oomph than the last discontinued XServe. I have a few out there that have been running flawlessly for many years, and the processors rarely get a workout.
Minis are a good alternative. Fusion drive may be worth looking into.
Thank you Scott. Good to know.