Not the ones I use.

But actually, there are other benefits: easier to add new lines to the list (just duplicate the previous one and change the value; no need to remember to add a comma at the end of the last item).

Also, someone mentioned another (small) benefit in the comments: when diff'ing files, using comma-first will only cause one line of difference, instead of two.

These are all small benefits, but since I can't think of any disadvantages to the comma-first style, I think I'm a new "convert".