I love how Fences honors the Windows setting for desktop icon size and spacing. It even responds to the Ctrl + mousewheel ability to resize the icons, and the fluid animation that reorders the icons works perfectly. I also like how the scrollbar only appears on mouseover. Very polished.
I did notice, however, that when I resize the icons to become smaller (say, 16x16), the icon text (which doesn't change in font size) starts to bleed outside of the fence margin.
This could be compensated for by having a padding buffer (around the perimeter of the fence) that is either manually set or is engaged when the icon size is smaller than a certain threshhold size.
Overall, Fences works great. I haven't had any problems with it, and I think it is a wonderful app.