I use OM first grade. It is more intense than K imo, but I am so far sticking with it. I like the way it approaches learning for my dc, so I guess that's incentive.
I have been getting more interested in MFW, but not enough to fully research it yet.
Also, since I did K with OM, I have a lot of the supplies already, and I like the crafting and festivals. I'm not so into worksheets. So it works for us right now.