I didn't get on that well with the Magic Mary. I think it's something that either fits your terrain and trail surface or it really doesn't. I found it kindof squirmy and unpredictable, but more planted in wet surfaces. It is considerably lighter than others in the same category but I think the tread pattern slows it down.
I haven't run a Hillbilly, but isn't that a mud tire? I've had mixed luck with Specialized tires, most of them weep badly and have very thin casings.
I have run the Assegai and I'm not sure it really fits in the same category as the other two. IMO it seems better suited to hardpacked surface and park riding rather than all around riding, esp. if wet or mud is involved. I've been on a EXO+/3C model and the grip is decent, I'd say comparable to the DHF for sure, but with better braking and slightly more predictability. I feel it starts to suffer in loose or wetter terrain, though, and I had a few close calls with it trying to lean it over when I first got it. I haven't tried the MaxxGrip version since it only comes in DD or DH, which is unfortunate. I'm not sure I buy into the hype over this tire.
I know it is not on your list (sorry to be that guy), but I prefer the new Vigilante over the two you mention that I've tried. It's got the blocky tread pattern of the MM, but with a wider casing, better side knobs, and more durability. I think it corners better and is more confidence inspiring on non-hardpack surfaces than the Assegai is, along with being more compliant and higher volume. If you ride in mud or wet stuff, the Assegai clears out alright, but the Vigilante is much better at that and I've run it in some very sloppy conditions where it worked great. The only time I'd take the Assegai over the Vigilante is if I was riding a lot of hardpack surfaces, which would wear down the knobs. The only downside is weight, the WTB tires run on the heavier side, but the casings seem thicker.