onehundred80, if the micro pod works exactly the same as a DRBIII then the ABS pump will run for about 2 seconds when the DRB III conducts a test of the system. Will a test show a sticky valve?
Mercedes dealers use a pressurized tool to flush/replace brake fluid.
As to replacing the ABS module it is rather straight forward. After disconnecting the electrical connection, loosen the two screws on the front of the ABS unit ( I think they are allen head) from the mounting bracket and the steel lines from the top; put new unit in place and reconnect lines and electric. It is very difficult to pull the unit out with the bracket attached. Those grommets are tight.
I have both a Limited and a SRT 6 in my garage and have just measured the diameter of the mastercylinder external and the two are identical at 31.3 mm. They are both marked with an H which I believe is a casting mark. Checking the part numbers at Mercedes I found both the master cylinder and the booster are the same part number, so it would seem that the longer travel on the SRT 6 is the result of the larger calipers on the front of the car.
Now, is the foot travel on your car longer and/or softer than other SRT 6. Pehaps a comparision with several other cars would be helpful; You should make a trip to the Dragon this fall and make the comparison.