best avchd for slow motion?
 

so I am in a loss to decide which I want, the HF10 for the 24p as well as the fact that I have a large collection of canon HD cams from the hg10, hv20, xhg1, xha1 and xlh1. Or do I go for the sony sr11 which has some of the more impressive and interesting technology in its face detection. Now I am losing the 24p but may be gaining the high speed 240fps for slow motion and while not certain that is enough it may well be for some special effects here and there.

So what other cameras flash based or possibly harddrive based can do as good, or better with slow motion if any? and what would be the noticeable difference between shooting at 240fps or shooting it normally, 24 or 60, and slowing it down in post?