Personally I've got and like Dungeoncraft and Monster Handbook, and will probably get CityCraft and possibly Portals.
But I do look twice at FFG stuff - the books are slightly more expensive than average, and have somewhat fewer pages (take for example - Dungeoncraft $24.95 around 170pp, Scarred Lands Ghelspad $24.95 and 250pp, spine is about the same width, and in fact at our local store - this is in the UK - the Scarred Lands book was somewhat cheaper).
The reason for this would seem to be the FFG paper stock, which additionally causes the books to be lighter and not to automatically stay open at the page you want (try it). So given this slight annoyance factor and the price/page factor they're not books I automatically buy.
PS: this may change though - I notice Creature Collection Revised is $29.95 and 250pp so other publishers may start to outstrip them.