Just finished the second set of Black Knights and I've hit the wall. I ran out of steam after just 9 minis (which is about right for me). I had to take a little break before finishing the last 5. I work on the Khorne Helbrute for a little bit to refresh and unwind.
The client requested that the minis be painted fast but did not care if they were painted to my best standard. That is not how I normally roll but I bit anyway. Now that I am 2/3rds of the way through, I am regretting that choice. Rather than zipping through them, I ended up painting them a little better than we negotiated and it took longer than I anticipated. In the future I don't think the "more faster" is a plan that is going to work for me.