Improvement of Minimum description length (MDL) estimate
For lower number of samples the preferred algorithm is the Akaike Information Criteria (AIC). Both are not optimal in any way, though MDL is a consistent estimator of model order.  The difference between them is the penalty term and not another estimator (other than ML)

I refer you to Petre Stoica paper on model order selection which gives a great summary of algorithms. 

I am also interested to hear more about your algorithm.