I love vim and NerdTree, but I'm sick of the fact that seemingly every time I try to open a file for viewing, half the time it get's rid of the old file I was editing and just opens it, and the other half splits the panel in half and makes me look at two pages.
Split screen would be useful on occasion, but I can't figure out why NERDTree does it sometimes or not. I'm just going over to the file in the tree and hitting enter. No idea what's going on, but it's a little annoying.