I have lots of questions and very few answers without alot more information.
1. What characteristic would you like to use to evaluate 'efficiency'?
2. What characteristic would you like to use to evaluate 'best'? If whatever your characteristic for 'best' is, how much does the results have to vary before you declare one is 'best'?
3. There are numerous population 'parameters' that one can evaluate from 'random samples' from said population. Are you attempting to estimate these parameters? If so, by what method? Confidence intervals, tolerance intervals, something else? Is there a time series component to the data or decisions at hand?
4. Is this an academic exercise or one that has practical decisions behind it? If the latter, please articulate more of the practical problem, sampling method (truly random...or something else), and the actual decisions at hand.
5. What do you know about measurement noise/variation with respect to the processes in play?
6. I hope you have examined the data graphically BEFORE doing any numeric analysis. There may be outliers, suspicious observations, or other features in the sample data sets that make any one specific numeric analysis approach more problematic than alternative approaches.
I've probably not touched on everything but the above is a start?