I have used Look style road pedals and cleats with float.

I currently have the Shimano A530 (spd) pedals on both of my bikes (road and "urban" mtb) with the SH51 cleat. The SH51 has about 4 degrees of float.

I find to get the most from the float, I need to be sure the cleat is positioned in the middle of my most comfortable foot travel. Takes some time, but worth the effort. Plus, while I was going through all the adjustments, if my knee felt weird, I could unclip and ride on the flat side of my pedals.

Good luck.