Both are great, I've used both extensively for Whitetail. I also used to use the now discontinued 220 gr version of the Phantom. Killed a bunch of critters with them but rarely had the bleeders last more than one animal unlike the woodsman which are very durable. The only difference between the muzzy phantom weights I believe is the steel ferrule as opposed to aluminum with the 125 grain...the 100 grain is a smaller broadhead than the 125 and old 220 versions. I shot the 100 grain version when I used a compound.
I'd say the woodsman heads are much more durable than the Phantom and easier to sharpen, stainless so they do rust though.