I've had both kits. OME is an easier install, rides nice and is less expensive. CALMINI rides VERY rough, costs more and is a tougher install. However, CALMINI gives you more real travel, as it does not use a spring spacer. It also repositions the front wheels to give more clearance in the wheelwell. The lack of a diff drop solution with OME was never a problem for me. The CALMINI kit probably needs it (especially if you remove the front sway bar), because it'll lift the front about 3 inches or more until it settles. It's a tough call. Figure out what's most important to you, then git-r-done! Good luck!
P.S. - If you get CALMINI, you may need to modify any front skid that covers the front diff and oil pan, since the diff will drop slightly lower than the crossmember. Just another thing to consider.