Using method_opt option in dbms_stats

   Hi

I have been accomplishing all the stats gathering operation through analyze table table_name compute statistics. The gather stats job is not scheduled yet. I would like to test the same in development before implementing the same in the Production. I would like to know the the behaviour of method_opt parameter during the stats gathering operation. I have gone through many blogs but havent found anything confirming what should be used.

The three options I am aware are:
i) for all columns size auto - Lets Oracle gather stats and build histograms for all the columns where needed. Trust Oracle for the best but some blogs write there are unwanted histograms collected. So should we try this or not.