This may be one of the very few positive-toned messages on this board, but I've ancedentally noticed that the behavior seems improved with respect to making outgoing calls.
About a month ago my iPhone 4S would very rarely make an outgoing call without the dreaded 'call failed' problem and would usually take three attempts before it would work. The wife's iPhone 4 never seemed to have this problem.
Recently I've noticed that this hasn't been happening for either of us anymore and nearly every time I try to make a call, it works on the first attempt. Nothing has changed on my end (haven't touched the microcell other than power-cycling a couple of times).