I have no reason to dislike Leopard. The installation on my MacBook went just fine and I've experienced no system problems, slowness, or other complications that others have unfortunately ran into. I don't make a habit of applying third party tweaks or use any file scrubbers, so maybe that has something to do with the lack of problems. Just a guess.
There are UI and other enhancement updates that I don't really care for... Stacks, the new Spotlight window (or lack thereof), certain folder behaviors... but nothing that I can't work around until Apple improves them or until I learn to live with them.
Unless you depend on third party software which hasn't received an upgrade to be compatible with Leopard (such as most Adobe products), I would go ahead and take the plunge and install it. Do a thorough backup beforehand in case of unexpected problems, of course.