All depends what you want from a controller.
For me I use servos on fairly big machines, I want 24v I/O and lots of them, if Step/Dir I want differential, I want analogue I/O etc etc so the CSMIO/IP-S or IP-A are what I would choose.
Lots of other controllers about theough, SmoothStepper, Kflop, PoKeys, UC100/300, DSPMC etc etc, but as said it all depends on what you want as some are perfect for small machines with steppers where others are beter for servo machines.
Hood