IIRC, LE2005 was originally supposed to be 10.2 until Mandrake merged with Conectiva. Mandriva is now on a one year release cycle instead of 6 months. They released LE2005 to appease the loyal customers who were anticipating the release of 10.2.
I wouldn't expect any real differences (besides newer packages/kernel/drivers) since the merger with Conectiva was so recent. I am still on 10.1 myself but if I were installing today I would go with LE2005.