I wouldn't mind having a lockup clutch, but I didn't do any tranny mods when I got my serval, wish I had. If you don't do the tranny mods, you probably won't want a lockup.
Those are what I have been running on my 421 serval in the trails, the do fucking sweet compared to any of the other tires I have used (holeshot hd, maxis razor, Dunlop) I'm sold on em