I use data.table and like it. It's fast (and I think memory efficient). plyr is IMO so slow to be unusable on just hundreds of thousands rows. dplyr, as ment

I use data.table and like it. It's fast (and I think memory efficient). plyr is IMO so slow to be unusable on just hundreds of thousands rows. dplyr, as mentioned, is the replacement that fixes it, but it was literally first released a couple months ago this year. I have no doubt Hadley will produce something brilliant, but I'm guessing it will undergo a lot of change to get there.