i don't even think i'll install leopard right away.. considering the amount of bugs.. i don't mind waiting til 10.5.1 comes out.
I have to say I have not experienced any problems with Leopard on My 2.16 GHz MacBook with 2GB of Ram and 160GB hard drive. No bug at all, I just did a clean install since most people who did an upgrade install had some issues as well as archive and install. Leopard seems to be 10-12 seconds faster at load up and faster in general especially when opening applications.
It does not have any noticeable bugs that will keep you from being productive. None here so far.