I know a bit of both Erlang and Lisp, but am an expert in neither. While looking around before picking up/learning more Erlang or Lisp for serious work, I came upon LFE and it seemed rather perfect (to me, and yes, I have looked at, and decided against, Elixir and a host of other things for myriad reasons) - Lisp with the Erlang VM (BEAM).
Looking a bit deeper, I find even Erlang can do things like functions to update functions (using abstract form http://erlang.org/doc/apps/erts/absform.html), similar to what Lisp macros would do (I only presume this, not knowing too much about either).
What are some useful things that can be done easily using LFE (Lisp flavored Erlang) but not (or would require a lot of effort in) vanilla Erlang? Are there any unique advantages (let's not talk about the syntax please, I'm so over it, fortunately) to doing LFE over ordinary Erlang?