I'm having serious 'bucket envy'. That's a great looking setup. I'd really like to know where you got that control stick knob. That looks much more elegant than mine.
I have a grapple for my loader which I did have to plumb off the boom circuit instead of the bucket circuit. I found it was just too awkward to not be able to roll the bucket back while closing the clamp and the same time, or the reverse, dump the bucket while opening the clamp. The stutter-step back and forth to do both made for a lot of loader rattling. And the original set up as it came from the dealer was even worse...to curl the bucket, the stick goes left, then to clamp down you had to go back to nuetral, press the button, then go full right past the de'tent. Ugh.
With the plumbing off the boom circuit you can simultaneously curl the bucket and clamp, or dump the bucket and open...it just seemed a more natural motion. I'm sure you could get use to doing it either way...except for the dealers way...that was rediculous.