all the feedback Ive heard regarding people that have converted to an X-Eng type of disc hand brake is that they are great.
As they're a disc, they are open and easy to clean after going off road. Being a disc, they work much better than the standard drum / shoe arrangement fitted to LR's as standard - especially if you do a lot of off road work - the drum just gets full of mud n water, then the shoes and brake mechanism inside just rust/seize up!
The conversion isn't cheap one though. However, if you intend to keep your motor for a fair while and/or do lots of off road work with it, then it'll probably be a good investment.