Yes..
Just to clear this up, ledu client and ledu data are two different things.
The ledu client is just a new .exe wich can read more .wil files than the normal one can, and it can be used on 1.4 servers also, but be aware that you need to use the new gamegate (search for it using the magical search tool

) wich would block the cheats BUILT IN TO THE LEDU CLIENT.
The ledu data, is just a set of .wil files (all types of them) wich can only be read by the ledu client, as the old client doesnt read so many .wil files, so basically it allows you to have more stuff on your server.