I never took the time to learn it, so, it kicked out time to time when I needed to keep it and every time it didn't let go the rope when I wanted... truly, that sucks.
The small biner is one more thing to do and doesn't match with the KISS principle. It's a good trick for ascending the bigs trees, but not for working in the canopy.
Petzl sells now a lock which we can add to the Pantin and make it acts like a Croll or a hand ascender.
I have a CT one now. Much more reliable, but you have to open the lock manually like the other toothed cam ascenders. It takes more time and more care to take the rope out. Not so easy with the spurs too.
Can't we have both properties in one device? Easy on, easy off, but hold it securely in the middle?