The differences are not that easily noticed. LW has done a good job of adding some perks (finds a few more sources, slightly better connections and . . . ?) that help make downloads faster, without crippling the free Basic version. The exact technical differences are probably tweaked with each version.

IMO the real difference is that Pro helps keep the project evolving and so they don't have to develop a big sales staff. I guess the bottom line is get Pro because you don't want to leech off the work of the developers.

btw--if the Free doesn't work on a set-up, the Pro won't either. There's no trickery in the Basic development to sucker people into Pro.