I think early Fall planting is better whenever possible. Every now and again, I've found myself in situations where I've planted a group of bulbs in early to mid-October, then changed my mind about location and dug them up and moved them to a different spot a couple weeks later. In all instances, it's amazing how much the bulb(s) progressed. Lots of tiny little roots had sprouted all around the parameter of the basil plate. The larger anchor roots had expanded to their original size and they too, had tiny little hair-like roots developing all along, up and down them. And, the bulbs themselves had become larger, more solid and looked brand new all over again. It's been pretty darn obvious that bulbs such as these were well on their way to being well established and acclimated for a good 'on time' show of flowers next Spring.
Of course, it's not always possible to plant in the Fall. For most of us, there's always something new for Spring that we want. But I view those Spring purchases as starter bulbs--to get a start of something for the following year and only allow one flower per plant for ID verification.