...for first-timers. I think it's a good cross between Birnbaum and UG. It's not to rah-rah (Birnbaum), and it's not overly comprehensive (UG). UG has a TON of information in it, and I think it could be overwhelming to a newbie. Frommers is more condensed, ie. highlights of each category of resort rather than every resort, highlights of restaurants in each park, not every restaurant in every park, etc. It does cover every attraction so their coverage of the rides, which I consider essential, is complete.
Now, if they get hooked, and they plan to go back, they need UG to learn all the ins and outs.