Quite a number of experienced 737 captains I know reduce thrust to idle earlier than the AT does, and avoid float by doing this. I have done so myself, by retarding the levers at about 35ft. This technique works well, in my experience, but there may be circumstances (eg significant headwind component, forward CG) in which it could bite you in the backside.
The float in a 'normal' 737 autoland is quite extreme, and uses lots of runway. Why? The aircraft was never designed to autoland, but the feauture was bolted on. The autopilot isn't properly capable of autoland, and relies upon the trim bias applied. This has all sorts of implications, none of them good!