I've done a bit of reading about various chemo options and I recommend going to a good library and having a look at some of the latest info books on breast cancer treatment (think Mayo Clinic).
You could also ask your oncologist which of the two treatment options they would prefer. You are probably in a risk category in which the two treatment options are fairly similar and they are giving you the option to choose which is personally convenient.
I have read that the weekly taxol regime has a slight edge over the less frequent dosage schedule. Again, ask your oncologist for confirmation of this, and it may also make no difference to you personally because of the type and stage of your particular breast cancer - which is great!
Personally, I had four 3-weekly doses of AC, then 12 weekly doses of taxol with a the odd week off occasionally due to low white blood cell count. I had one lot of antibiotics and remained healthy throughout. I was able to do some walking and kept up a weekly Pilates reformer class with my physio.
Wishing you the best
Cheers
Meg