Great list, I voted Rex45, I have the most use time with it, and consequently the most sharpening time, my ranking would be...
...I must confess that while I do have a Maxamet rig, I have spent VERY little time with it, using or sharpening -- I wasn't really impressed or excited after carrying it as my EDC for a week immediately following purchasing it, and it's been sitting and waiting patiently ever since.
As of late I have been spending the majority of my 'new-steel' time to 4V, and so far I am very impressed with it, were this my top 4 current favourite steels list I would probably rank as such...
Anyhow, I can tear through a stupid ammount of cat3/5/6 cable, occasionally fiber-optic cable, ground wires (yeesh), zip ties, mule-tape, cardboard, blah blah -- I've found the best edge performance & stability in Rex45, and the easiest time getting back to scary after some real use/abuse... I am really wanting to get a Shaman or Manix2 in 4V so I can get some real hard time in, the Para3 I have is just not the ideal hard use platform for me... although I am getting a Tuff (3V) in a couple weeks and I'm super excited to see how that stands up...