DotNetMagic library or similar...

Guys,

I'm starting to work on a fairly big application that will
have some
windows. I'd like to use some window managers, like
DotNetMagic from
crownwood software or DockPanel Suite by Weifen Luo. I used
an older version
of both (the Magic library was free at the time), but I
don't have any
experience with the current versions of either. Did anyone
used these (or
something else worth mentioning)? What were your
experiences: was the one
used reliable, easy to use, etc? Is there any reason to go
with the Magic
library ($400) instead of using the free DockPanel Suite? Or
is there any
other products out there that are good?

Thanks,
Gyorgy Bozoki