The Leaders Club of the Leading Hotels of the World is a favourite hotel loyalty scheme of mine. It really does seem to make a difference at the hotel to the type of room allocated for your stay and the welcome gift in the room is a nice touch!
Leaders Club justr seems to be a reservation system. There are no guarantees of upgrades and the occasional free gift is always paid for in the rate. Rates are never any better than you can gain from booking direct. I have used them but am failing to see any benefit.
They often lose the fact that I am a member on my reservation, and fail to deliver any tangible benefits.
Given the relatively limited number of hotels which operate this scheme I prefer to stick with the majors like Intercontinental, who value my Royal Ambassador status (even though the recent changes in the programme have devalued it somewhat).