OpenCM9.04-C (with onboard XL-type connectors)

This product is plug and play. You can get some XL-320 servos going in just a few minutes. Can't wait to see different servo horns. Great products.

The OpenCM9.04 C Type is no slouch - it uses an ARM 32 bit M3 core - none of your A____o 8 bit stuff here. I have built up a free-RTOS-based library based on ARM 32 cores and setting this unit us as an autonomous node in a complex system is well withing my reach. Robotis has aimed this controller at their XL-320 family of low-end serially-addressable servos and it includes four sockets for daisy-chained XL-320 units. It can also be piggy-backed onto an OpenCM 485 EXP board that supports the beefier Dynamixel pro line of servos operating at 24 VDC.
The controller includes sockets for a Bluetooth interface as well as a number of accessories included with the Darwin-mini family - distance, color, ultrasonic, touch, object detection, DMS, magnetic and gyro sensors. Note that there are only a limited number of interface points on the controller so not all these sensors can be loaded onto a single controller (at least w/o developing a MUX daughter card).
The software still leaves something to be desired, owing much to the A___ino systems - there is no real time trace capability or easy way to organize the program load into the processor. However, this can be overcome by using the Open ST-Link debugger port provided you have invested in the appropriate debugging hardware and associated software.