CZ aren't strict at all about luggage when traveling in J/F, at least from my experience (I traveled with them extensively inside China with excessive hand luggage and never had a problem), in fact I really like CZ, they have an excellent hard product on most of the fleet and service is always polite, the only disadvantage would be the lack of English some of their crews have, plus the "joy" of connecting in Guangzhou (not that PEK is any better).