I bought this book since I'm a huge Buffy fan-boy, and even if you discount that, I still say it's one of the finest game products I've ever purchased (I've been playing for about 10 years, to give perspective on that).
I got it at GenCon last year, after hearing about it at the Buffy CCG booth. $40 was a steep price for a hardback book no larger than (maybe smaller than?) the 3E PHB, but hey, fanboyhood meant I could justify it.
I didn't have much time to look at it until 3 weeks later when things settled down a bit at work and the games I was running already (D&D and Exalted) were prepped enough. Then I cracked open the book and was *blown away*.
In all my years of gameplay I've neven beet the type to actually sit down and read a rules book. I flip through it, dig for ideas, and pull it out only when necessary. Example being the splat books for D&D - if I'm making a fighter I pull out S&F (and Quint. Fighter, etc...) to get ideas and look at the real mechanics on something, but otherwise the book sits unused on my shelf awaiting the next time it will be desired.
I've only ever actually read one game book from cover to cover - the Sabbat Guide for Mind's Eye Theatre Vampire (LARP). That book kicks ass and I don't even want to play Sabbat. It's just that well written.
Buffy RPG was the second book I ever read cover to cover. Every sentence gives new ideas or helps set the mood. It's all written just like an episode of Buffy, very casual and with plenty of self-referential humor. Golden.
I loved it so much, in fact, that I immediately purchased the limited edition of the book at my FLGS ($70) and then pre-ordered copies of Director's Screen ($20), Slayer's Handbook Limited Ed ($55), Monster Smackdown Limited Ed ($55), and Magic Box ($27). That's a lot of investment for me to make (a college student who only works 3 months a year) but I knew they'd all be great purchases. And thus far I've been anythng but disappointed by Slayer's Handbook and Monster Smackdown.
I really can't say enough good about this game. I've run 2 one-shots for some people around here to try and get the hang of running a television-type game (as opposed to a chronicle-type game that I'm more used to), and to see what players might want to play in it.
I've got a group of a couple guys interested in playing it this summer, but I really need to find a girl or two to even out the gender of the gaming group, since Buffy seems (IMO) to be a game that really *needs* both sexes playing it to be as good as it can be.
The mechanics are a joy after coming from the very laden and specific D20 System (which, don't get me wrong, I really like). They're simple as hell, use just 1d10 for all rolls (save for damage, which you needn't roll dice for anyways if you don't want to using a variant system in the book).
I found a copy of WitchCraft (uses almost the same system) for 60% off a couple weeks later and picked that up. It also kicks ass. Unisystem and Eden Studios have gained a lifelong fan in me from Buffy RPG. I got their catalog in the mail with my Monster Smackdown, and I found over $400 in books I wanted already. Compared to the very few D20 books I am at all interested in anymore (after blowing $1000 this year on them).
Trust me, if you like Buffy at all, you'll love the core book and the game in general. Finding players will be the real hitch, but since, in general, Buffy fans seem to clump together, you might not have too much trouble with that.
Long post, I know. So I'll close by saying that the game kicked my ass completely. It's one of the best I've ever seen in terms of production value, editing, mechanics, and just manaing to get that perfect 'feel' somehow. It's the best $40 I ever spent on gaming materials.