Cliff, I'm sure you've been asked this a million times...
In your book, your pretty adamant about using a choke pull-off. I've never had much luck with them (slow acting or otherwise), so I remove 'em.
My vehicles are all light and have high horsepower/torque. I also spend a great deal of time fine tuning the secondary air flap spring tension to ensure a smooth secondary transition.
Speaking of which, I remove the small spring on the side and use an accelerator pump spring on top of the secondary hanger to adjust the tension. I do this for two reasons, the slight friction on the hanger seems to help the transition and it doesn't require tools to adjust.
I don't use the secondaries when my engine isn't warm (bad idea anyway).
So if the transition is smooth from the primaries to the secondaries and you don't try to floor it when your engine is cold, is there a reason to use a choke pull-off that I am unaware of?