Here IMHO is what I see as benefits.
1. We got some Purple V11 to drop. If I can not use them I break them down for Crafting advancement.
2. We used the skill lines that needed advanced and they went up faster than normal grinding
3. We had fun doing it. Sometimes its just fun to run as a guild group and not worry about killing a big boss
4. We picked up 2 people in the group that were not in the guild, exposing the guild and what we do to others.
I do think it is still worth doing...looking forward to your comments