So angry.
Compared to Vista, Leopard will be a walk in the park, and while I am not psychic I am willing to bet on it.
Leopard will be a few months late, Vista was only a name change and 4 years late.... so I guess that's not much to compare it to.
Anyway, ofcourse there will be flaws, but as is the life of computers. Ignore Mr. Angry up there. Apple has issues, but not much worse, if at all, compared to the majority of computer companies, or software companies. I personally have never had a problem with an OSX operating system that warrented it really even being called a flaw. Safari is AOK for me. so I dunno.
Either way, it is up to you, but Leopard should be fine, and if there are flaws they will update them in software update quickly and efficiently (if past pretense means anything)
If you are asking becasue like you said you are new to mac, you are probably used to windows, and I don't think there is anything apple could do to OSX to make it that horrendous.
enjoy!