i used to be a bbedit head.

my favorite features (then) were good find-and-replace, preview in web browser (this was a big deal to me at the time, it's not any more), and a few of the extras, like "prefix/suffix lines with...".

my bbedit disappointments now (and i haven't used recent osx versions, so many of these may have been alleviated) are 1., utter, crushing lack of column editing (vertical/non-contiguous select) mode, 2. what felt like clumsier multi-window navigation (this is more a windows/mac gui toolkit issue than a bbedit-specific problem), and 3., it's not very "bare-bones" any more.

w/r/t emacs, emacs is wonderful. i would offer this caveat: if you are a programmer and a compulsive customizer like me, you will undoubtedly find yourself spending oodles of time customizing and extending your editor to make it just so.

if you do more unix-related work, emacs wins. by unix-related, i mean, you are comfortable with unix or want to become so, and plan on using different shell commands as part of your editing/emacs-ing. emacs has mail and customization like nobody's business, which are the reasons *i* like it. xemacs is my preference, via an xserver. other people will have others.

if you do more "native" work, then prolly another (bbedit, etc.) more gui-integrated, limited but simpler editor wins.