For my zone, My experience tells me cuttings are best taken just before bud movement which is
around end February or March. Cuttings taken around this time in my zone have tendency to root
much easier & healthier. What's your experience ???

i don't really notice that much difference between cuttings taken in fall and in spring. as long as they are super fresh, they seem to root fine.

paully22, by theory, you are absolutely right. The concentration of Fitoestrogen at the buds force buds to grow open and same time sugars start coming back up towards buds from the root system of the plant, meaning, those times the cambium is at it's best with sugar contents and all other enzymes to feed the new growth and Fitoestrogen which is plant version of growth hormone supplied by nature.

I think once the plant has had a period of dormancy and the branches and buds have had time to mature/harden they can be taken without loss of potential.  They can be forced to root anytime after that but come spring it does seem they grow faster. 

In the more challenging climate zones you need to take a balanced approach and ensure you harvest the cuttings before they suffer winter injury.

Paully, I totally agree. The cuttings that I get in the fall versus the ones that are taken after January are a night and day difference for me. The cuttings taken later seem like they just can not wait to grow. For me, they root 2 or more weeks sooner and the roots usually fill the cup in half the time as well.
Pino is right on also in regards to harvesting cuttings before any damage occurs.