errorest slow

Hi ,
When using errorest on a large dataset (12000 variables) it performs
very slow. By looking at the randomforest package it says that for
largedatasets the use of the formula is discouraged.

So it's better to use the x and y terms as the example below:
rf<-randomForest(x=df[trainindices,-1],y=df[trainindices,1],xtest=df[testindices,-1],ytest=df[testindices,1],
do.trace=5, ntree=500)

Would it be possible to modify errorest so that it uses x and y rather
than formula. I think that would increase speed on large datasets.

errorest(type~.,data=mydate, model=randomForest,mtry=2)#will perform slow
errorest(x=type,y=variables,data=mydate,
model=randomForest,mtry=2)#would perform faster if implemented

thanks,
david