Both arms straight?
 

I'm working on my aquired motion and I find it difficult to stop at both arms straight. Many times I find myself in my full balanced finish. Jeff Hull makes this look so easy...

Is this a sign of holding on or a late swivel or maybe something else?

I attended the So. Cal school with Yoda & Yoda's Luke late last year but I've been away from the TGM fold for awhile.

I would say that you just need to start out by doing things at a speed, that will allow you to achive your goals.

Start with One arm only.
 

I'll do it with one arm (either arm) only first and do the same with the other jointed.

rhythm & lag
 

I will expound a little about how I understand "speed". I have struggled some with the aquired motion stopping at follow through, also (among other things). In my own experience, I must prepare for the proper amount of lag loading and maintain a consistent rhythm throughout the stroke. Monitor the lag at the transition from back to forward. Load it just enough to make a smooth, steady, heavy stroke through the ball so that the club will stop at both arms straight. If you load too much lag, you will either quit or hit the ball too hard (going past both arms straight). Also, make sure the rhythm is consistent. Do not make any compensation for or because of the ball. Every stroke goes from Start Up to Top/End to Finish. You must program from start to finish before Start Up. Make sure your program includes the proper lag loading and rhythm, then forget about the ball and make the programmed motion.

Remember, Lag is the Secret of GOLF!