I would have to say that under normal conditions, you would want to trim them to provide better air circulation to the peudostem and to prevent fungus and insects that tend to love warm moist areas. At the moment, the benefit to leaving them is that they provide protection for the pseudostem (like wrapping them would) in case of another freeze. I will be pruning mine probably the 2nd or 3rd week of March as we have been known to get an occasional late freeze. Actually, when I left for work this am, there was frost on the cars even though the radio said it was in the mid-upper 40's. When I do trim the leaves, I cut them up and kind of bury them around the base of the trees to compost.
